Search results
1 – 10 of over 308000Traffic signal control is one of the oldest application areas of fuzzy sets in transportation. In general, fuzzy control is found to be superior in complex problems with…
Abstract
Traffic signal control is one of the oldest application areas of fuzzy sets in transportation. In general, fuzzy control is found to be superior in complex problems with multi-objective decisions. In traffic signal control, several traffic flows compete for the same time and space, and different priorities are often set to different traffic flows or vehicle groups
The public transport priorities are a very important part of the effective traffic signal control. Normally, the public transport priorities are programmed by using special algorithms, which are tailor-made for each intersection. The experiences have proved that this kind of algorithms can be very effective if some compensation algorithms and the traffic-actuated control mode are used. We believe that using the fuzzified public transport priority algorithms, the measures of effectiveness of traffic signal control can be even better. In this paper, our fuzzy control algorithm of the public transport priorities will be presented.
Shaoming Zou, Charles R Taylor and Er (Eric) Fang
While it is widely acknowledged that host governments play some role in framing the governance structure that is available to multinational corporations, some argue that in recent…
Abstract
While it is widely acknowledged that host governments play some role in framing the governance structure that is available to multinational corporations, some argue that in recent years the influence of host governments on MNCs in terms of the level of ownership and control over their foreign ventures has diminished. The authors examine the degree of MNC’s control in foreign investment by presenting and testing a model of government influences on MNC’s control over its foreign market venture. Based on a survey of U.S. MNCs, the authors find that host government preference does influence MNC’s ownership control over its foreign market venture, which in turn influences its management control over the venture.
The most basic solution for monitoring position and attitude of an UA is through direct line-of-sight. Because they are usually standing outside, a pilot that maintains direct…
Abstract
The most basic solution for monitoring position and attitude of an UA is through direct line-of-sight. Because they are usually standing outside, a pilot that maintains direct line-of-sight with the aircraft is usually referred to as the EP, as opposed to an internal pilot (IP) who obtains position and attitude information electronically while inside of a ground control station (GCS). Flight using an EP represents the most basic solution to the problem of separating the pilot from the aircraft while still enabling the pilot to monitor the location and attitude of the aircraft. Pilot perspective is changed from an egocentric to an exocentric point of view. Maintaining visual contact with the UA, the EP can control the aircraft using a hand-held radio control box. Many of these control boxes are similar to those used by radio-controlled aircraft hobbyists and provide direct control of the flight surfaces of the aircraft through the use of joysticks on the box. Very little automation is involved in the use of such boxes, which control the flight surfaces of the aircraft.
Lubov I. Vanchukhina, Nelly N. Galeeva, Yulia R. Rudneva, Anastasia M. Rogacheva and Tamara P. Shamonina
Nodirbek Bakhromzhon Ugli Anvarjonov, Ki-Hyun Um, DeYu Zhong and Eun-Kyu Shine
The principal research objective entails examining the nexus between green supplier selection and green performance while scrutinizing the moderating role of governance…
Abstract
Purpose
The principal research objective entails examining the nexus between green supplier selection and green performance while scrutinizing the moderating role of governance mechanisms, specifically process control and outcome control, in shaping this association.
Design/methodology/approach
To assess our hypotheses, this study obtained data from Chinese manufacturing sectors and utilized regression analysis on a dataset consisting of 295 samples.
Findings
This study enriches the sustainable supply chain management literature by emphasizing the influence of green supplier selection on a firm’s green performance and the moderating effects of outcome and process control, offering practical insights for industry professionals.
Originality/value
This study enriches the sustainable supply chain management literature by emphasizing the influence of supplier selection on a firm’s environmental performance and the moderating effects of outcome and process control, offering practical insights for industry professionals.
Details
Keywords
Curt Adams and Olajumoke Beulah Adigun
This study addressed a relatively understudied process of school leadership: the principal-teacher conversation about instructional change. Two distinct conversation structures…
Abstract
Purpose
This study addressed a relatively understudied process of school leadership: the principal-teacher conversation about instructional change. Two distinct conversation structures were examined: controlling conversation and transformative leadership conversation (TLC). Self-determination theory (SDT) was used to make the case that TLC is a better fit for instructional change than controlling conversation. Hypotheses were developed on the relationship between principal-teacher conversation and teacher trust in the principal, teacher autonomy and teacher vitality. These mental states were identified for empirical testing because of their influence on change processes.
Design/methodology/approach
The empirical study used a correlational research design with survey data. The data came from a random sample of 2,500 teachers from the population of certified teachers in a southwestern state in the USA. Useable survey responses were obtained from 1,615 teachers, for a response rate of 65 percent. Teachers in the sample averaged 15 years of teaching experience, with 7 years in their current school. Around 81% of teachers identified as female and 18 percent as male and 79% of teachers listed a racial identification as white. Hypotheses were tested in a path model using AMOS 28.0 with robust maximum likelihood (MLR).
Findings
As hypothesized, TLC had moderate to strong positive relationships with teacher trust in the principal, teacher autonomy and teacher vitality. Controlling conversation had small, negative relationships with teacher trust in the principal and teacher autonomy. Controlling conversation was not related to teacher vitality in the path analysis. Compared with controlling conversation, TLC had stronger relationships with teacher mental states.
Originality/value
The results of this study begin to reveal useful evidence on the inherent social-psychological mechanisms active in principal-teacher conversations. With results indicating that conversation structure has consequences for positive teacher mental states, the study directs attention to a ubiquitous yet understudied leadership process.
Details
Keywords
Ziyuan Ma, Huajun Gong and Xinhua Wang
The purpose of this paper is to construct an event-triggered finite-time fault-tolerant formation tracking controller, which can achieve a time-varying formation control for…
Abstract
Purpose
The purpose of this paper is to construct an event-triggered finite-time fault-tolerant formation tracking controller, which can achieve a time-varying formation control for multiple unmanned aerial vehicles (UAVs) during actuator failures and external perturbations.
Design/methodology/approach
First, this study developed the formation tracking protocol for each follower using UAV formation members, defining the tracking inaccuracy of the UAV followers’ location. Subsequently, this study designed the multilayer event-triggered controller based on the backstepping method framework within finite time. Then, considering the actuator failures, and added self-adaptive thought for fault-tolerant control within finite time, the event-triggered closed-loop system is subsequently shown to be a finite-time stable system. Furthermore, the Zeno behavior is analyzed to prevent infinite triggering instances within a finite time. Finally, simulations are conducted with external disturbances and actuator failure conditions to demonstrate formation tracking controller performance.
Findings
It achieves improved performance in the presence of external disturbances and system failures. Combining limited-time adaptive control and event triggering improves system stability, increase robustness to disturbances and calculation efficiency. In addition, the designed formation tracking controller can effectively control the time-varying formation of the leader and followers to complete the task, and by adding a fixed-time observer, it can effectively compensate for external disturbances and improve formation control accuracy.
Originality/value
A formation-following controller is designed, which can handle both external disturbances and internal actuator failures during formation flight, and the proposed method can be applied to a variety of formation control scenarios and does not rely on a specific type of UAV or communication network.
Details
Keywords
Min Zeng, Jianxing Xie, Zhitao Li, Qincheng Wei and Hui Yang
This study aims to introduce a novel technique for nonlinear sensor time constant estimation and sensor dynamic compensation in hot-bar soldering using an extended Kalman filter…
Abstract
Purpose
This study aims to introduce a novel technique for nonlinear sensor time constant estimation and sensor dynamic compensation in hot-bar soldering using an extended Kalman filter (EKF) to estimate the temperature of the thermocouple.
Design/methodology/approach
Temperature optimal control is combined with a closed-loop proportional integral differential (PID) control method based on an EKF. Different control methods for measuring the temperature of the thermode in terms of temperature control, error and antidisturbance are studied. A soldering process in a semi-industrial environment is performed. The proposed control method was applied to the soldering of flexible printed circuits and circuit boards. An infrared camera was used to measure the top-surface temperature.
Findings
The proposed method can not only estimate the soldering temperature but also eliminate the noise of the system. The performance of this methodology was exemplary, characterized by rapid convergence and negligible error margins. Compared with the conventional control, the temperature variability of the proposed control is significantly attenuated.
Originality/value
An EKF was designed to estimate the temperature of the thermocouple during hot-bar soldering. Using the EKF and PID controller, the nonlinear properties of the system could be effectively overcome and the effects of disturbances and system noise could be decreased. The proposed method significantly enhanced the temperature control performance of hot-bar soldering, effectively suppressing overshoot and shortening the adjustment time, thereby achieving precise temperature control of the controlled object.
Details
Keywords
This study seeks to explicate how institutional disruptions impact multinational corporation (MNC) subsidiary control choices. It uses institutional theory to understand the…
Abstract
Purpose
This study seeks to explicate how institutional disruptions impact multinational corporation (MNC) subsidiary control choices. It uses institutional theory to understand the influence of formal and informal institutions across countries on the type of control system employed in an MNC manufacturing subsidiary.
Design/methodology/approach
This study’s sample is based on a unique dataset from five trustworthy sources. We use multi-level models to account for the hierarchical nature of the sample of 1,630 multinational subsidiaries spread across 26 host countries by firms from 21 home countries.
Findings
The institutional distance between the host and the home country has a negative relationship with strategic control. In contrast, the home country’s power distance has a positive relationship with strategic control.
Originality/value
Study findings indicate the need to incorporate formal and informal institutional elements in the control system’s conceptual framing and design. This notion complements existing visualizations of optimizing MNC controls through extant articulations of minimizing governance costs through organizational design choices or strategic needs.
Details
Keywords
Abdelmoneim Bahyeldin Mohamed Metwally and Ahmed Diab
In developing countries, how risk management technologies influence management accounting and control (MAC) practices is under-researched. By drawing on insights from…
Abstract
Purpose
In developing countries, how risk management technologies influence management accounting and control (MAC) practices is under-researched. By drawing on insights from institutional studies, this study aims to examine the multiple institutional pressures surrounding an entity and influencing its risk-based management control (RBC) system – that is, how RBC appears in an emerging market attributed to institutional multiplicity.
Design/methodology/approach
The authors used qualitative case study research methods to collect empirical evidence from a privately owned Egyptian insurance company.
Findings
The authors observed that in the transformation to risk-based controls, especially in socio-political settings such as Egypt, changes in MAC systems were consistent with the shifts in the institutional context. Along with changes in the institutional environment, the case company sought to configure its MAC system to be more risk-based to achieve its strategic goals effectively and maintain its sustainability.
Originality/value
This research provides a fuller view of risk-based management controls based on the social, professional and political perspectives central to the examined institutional environment. Moreover, unlike early studies that reported resistance to RBC, this case reveals the institutional dynamics contributing to the successful implementation of RBC in an emerging market.
Details