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1 – 10 of 722Slawomir Koziel and Anna Pietrenko-Dabrowska
A novel framework for expedited antenna optimization with an iterative prediction-correction scheme is proposed. The methodology is comprehensively validated using three…
Abstract
Purpose
A novel framework for expedited antenna optimization with an iterative prediction-correction scheme is proposed. The methodology is comprehensively validated using three real-world antenna structures: narrow-band, dual-band and wideband, optimized under various design scenarios.
Design/methodology/approach
The keystone of the proposed approach is to reuse designs pre-optimized for various sets of performance specifications and to encode them into metamodels that render good initial designs, as well as an initial estimate of the antenna response sensitivities. Subsequent design refinement is realized using an iterative prediction-correction loop accommodating the discrepancies between the actual and target design specifications.
Findings
The presented framework is capable of yielding optimized antenna designs at the cost of just a few full-wave electromagnetic simulations. The practical importance of the iterative correction procedure has been corroborated by benchmarking against gradient-only refinement. It has been found that the incorporation of problem-specific knowledge into the optimization framework greatly facilitates parameter adjustment and improves its reliability.
Research limitations/implications
The proposed approach can be a viable tool for antenna optimization whenever a certain number of previously obtained designs are available or the designer finds the initial effort of their gathering justifiable by intended re-use of the procedure. The future work will incorporate response features technology for improving the accuracy of the initial approximation of antenna response sensitivities.
Originality/value
The proposed optimization framework has been proved to be a viable tool for cost-efficient and reliable antenna optimization. To the knowledge, this approach to antenna optimization goes beyond the capabilities of available methods, especially in terms of efficient utilization of the existing knowledge, thus enabling reliable parameter tuning over broad ranges of both operating conditions and material parameters of the structure of interest.
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Competition among higher education institutions has pushed universities to expand their competitive advantages. Based on the assumption that the core functions of universities are…
Abstract
Purpose
Competition among higher education institutions has pushed universities to expand their competitive advantages. Based on the assumption that the core functions of universities are academic, understanding the teaching–learning process with the help of student evaluation of teaching (SET) would seem to be a logical solution in increasing competitiveness. The paper aims to discuss these issues.
Design/methodology/approach
The current paper presents a narrative literature review examining how SETs work within the concept of service marketing, focusing specifically on the search, experience, and credence qualities of the provider. A review of the various factors that affect the collection of SETs is also included.
Findings
Relevant findings show the influence of students’ prior expectations on SET ratings. Therefore, teachers are advised to establish a psychological contract with the students at the start of the semester. Such an agreement should be negotiated, setting out the potential benefits of undertaking the course and a clear definition of acceptable performance within the class. Moreover, connections should be made between courses and subjects in order to provide an overall view of the entire program together with future career pathways.
Originality/value
Given the complex factors affecting SETs and the antecedents involved, there appears to be no single perfect tool to adequately reflect what is happening in the classroom. As different SETs may be needed for different courses and subjects, options such as faculty self-evaluation and peer-evaluation might be considered to augment current SETs.
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Abstract
Purpose
Increasing carbon productivity is an effective way to reduce carbon emissions, while boosting economic prosperity. For appropriate formulating and enforcement of energy saving and carbon emissions reduction policies in various sectors, it is of great significance to investigate the evolution characteristics and convergence modes of carbon productivity across the manufacturing sectors.
Design/methodology/approach
Using slack-based measure directional distance function (SBM-DDF) and global Malmquist–Luenberger (GML) productivity index, this paper measures the carbon productivities of 29 manufacturing subsectors in Shanghai, China, from 2001 to 2016 under the total factor framework. Furthermore, based on the convergence theories, it empirically examines the convergence of carbon productivity across these manufacturing sectors.
Findings
The measurement results suggest that the carbon productivities of the manufacturing sectors in Shanghai show an increasing tendency on the whole, and technical efficiency instead of technological change makes a main contribution to the increase. It is found that there is no obvious σ convergence across the manufacturing sectors in Shanghai, but there exist both absolute ß convergence and conditional ß convergence. Moreover, there is heterogeneity in convergence characteristics between the clean sectors and polluting sectors. The findings also show that firm size and industry structure have significant positive impacts on the growth of carbon productivities of the manufacturing sectors, whereas the impacts of capital deepening and energy consumption structure are significantly negative.
Originality/value
This paper measures the carbon productivities of the manufacturing subsectors by applying SBM-DDF and GML index, so as to improve the accuracy. It provides an insight into the convergence of carbon productivity across the manufacturing sectors.
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Ming-Miin Yu, Bo Hsiao, Shih-Hsun Hsu and Shaw Yu Li
This paper presents an alternative approach to evaluating the overall efficiency and performance of Taiwanese container ports. Specifically, a parallel activity with series…
Abstract
This paper presents an alternative approach to evaluating the overall efficiency and performance of Taiwanese container ports. Specifically, a parallel activity with series structure concept in the form of data envelopment analysis (MNDEA) is used to construct a model that applies to three different activities: harbor management, stevedoring and warehousing operations. We will further divide each activity into two process types, production processes and services processes. We will also adopt a Delphi survey approach and use the Analytic Network Process (ANP) to identify these processes’influence dependence and their degree of importance for the MNDEA model setting. An empirical application demonstrates the performance of Taiwanese container ports by using MNDEA with window analysis techniques via the directional distance functionThe results demonstrate that the application is effective in indicating and/or suggesting resource-adjustments, while considering which undesirable output levels and shared inputs were involved. The results also present directions for possible improvements in workplace efficiency.
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Donghwan Ahn, Shiyong Yoo and Seungho Cho
This study investigates the effect of managerial ability on labor productivity by analyzing various methods in the firm-year panel data of listed firms in South Korea from 2002 to…
Abstract
This study investigates the effect of managerial ability on labor productivity by analyzing various methods in the firm-year panel data of listed firms in South Korea from 2002 to 2019. Managerial ability was analyzed using the measurement method of Demerjian et al. (2012), while labor productivity was analyzed using value-added and sales. The authors find that managerial ability has a positive effect on labor productivity. In other words, the productivity of employees improves with the appointment of a manager with higher abilities. The study’s findings suggest that firms should consider managerial ability as a means of improving labor productivity.
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Kuo-Chung Shang and Peter B. Marlow
Logistics and supply chain management has been elevated to a strategic level whereby firms can simultaneously achieve differentiation and low cost for sustained competitive…
Abstract
Logistics and supply chain management has been elevated to a strategic level whereby firms can simultaneously achieve differentiation and low cost for sustained competitive advantage. Empirical studies have often concentrated on logistics management in developed Western countries, displaying a bias towards the USA. This study applies the competency approach to explore logistics in Taiwan. A survey of 1,200 manufacturing firms was undertaken in order to examine the relationships between logistics competency, logistics performance, and financial performance, using exploratory factor analysis and the structural equation modelling technique. Four logistics competencies, namely, integration and knowledge competency, customer focused logistics competency, measurement competency, and agility competency were identified. The research findings revealed that (1) logistics competency was significantly related to logistics performance but not significantly associated with financial performance, and (2) logistics performance was positively associated with financial performance. These findings also implied that logistics competency has an indirect effect on financial performance through logistics performance. This finding confirmed the “world-class” logistics competencies (i.e. positioning, integration, agility, and measurement) as identified by MSUGLRT (1995). In addition, it suggests that logistics competency in a huge geographic area such as America can have the same effect in a smaller geographic area such as Taiwan.
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Francisco Javier Ayvar-Campos, José César Lenin Navarro-Chávez and Víctor Giménez
This paper aims to review the efficient use of economic and social resources to generate income and, at the same time, reduce the concentration of wealth in the 32 states of the…
Abstract
Purpose
This paper aims to review the efficient use of economic and social resources to generate income and, at the same time, reduce the concentration of wealth in the 32 states of the Mexican Republic during the period 1990-2015.
Design/methodology/approach
Data envelopment analysis with the inclusion of a bad output was used to diagnose the efficiency of Mexican entities, and the Malmquist–Luenberger index was applied to understand how this efficiency evolves.
Findings
The results clearly show that only 3 of the 32 units studied generated and distributed wealth efficiently, while the other 29 must increase their level of income and its distribution.
Originality/value
According to the authors’ knowledge, this is the first work that performs a temporal analysis of the efficiency in the generation of Human Development Index using bad outputs and the Malmquist–Luenberger index.
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The authors investigate the effect of a short-term stock return reversal on the term structure of momentum profits in the Korean stock market following Goyal and Wahal (2015)…
Abstract
The authors investigate the effect of a short-term stock return reversal on the term structure of momentum profits in the Korean stock market following Goyal and Wahal (2015). Their empirical findings show that the term structure of momentum is more pronounced when a return reversal lasts up to two months but is substantially weakened when past performance over the last two months is not taken into account for portfolio formation. Their evidence suggests that the term structure of momentum profitability arises primarily from a carryover of the return reversal from the previous two months.
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Mingjie Hao, Yiming Bie, Le Zhang and Chengyuan Mao
The purpose of this paper is to develop a dynamic control method to improve bus schedule adherence under connected bus system.
Abstract
Purpose
The purpose of this paper is to develop a dynamic control method to improve bus schedule adherence under connected bus system.
Design/methodology/approach
The authors developed a dynamic programming model that optimally schedules the bus operating speed at road sections and multiple signal timing plans at intersections to improve bus schedule adherence. First, the bus route was partitioned into three types of sections: stop, road and intersection. Then, transit agencies can control buses in real time based on all collected information; i.e. control bus operating speed on road sections and adjust the signal timing plans through signal controllers to improve the schedule adherence in connected bus environment. Finally, bus punctuality at the downstream stop and the saturation degree deviations of intersections were selected as the evaluation criteria in optimizing signal control plans and bus speeds jointly.
Findings
An illustrative case study by using a bus rapid transit line in Jinan city was performed to verify the proposed model. It revealed that based on the proposed strategy, the objective value could be reduced by 73.7%, which indicated that the punctuality was highly improved but not to incur excessive congestion for other vehicular traffic.
Originality/value
In this paper, the authors applied speed guidance and the adjustment of the signal control plans for multiple cycles in advance to improve the scheduled stability; furthermore, the proposed control strategy can reduce the effect on private traffics to the utmost extend.
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Yunfei Li, Shengbo Eben Li, Xingheng Jia, Shulin Zeng and Yu Wang
The purpose of this paper is to reduce the difficulty of model predictive control (MPC) deployment on FPGA so that researchers can make better use of FPGA technology for academic…
Abstract
Purpose
The purpose of this paper is to reduce the difficulty of model predictive control (MPC) deployment on FPGA so that researchers can make better use of FPGA technology for academic research.
Design/methodology/approach
In this paper, the MPC algorithm is written into FPGA by combining hardware with software. Experiments have verified this method.
Findings
This paper implements a ZYNQ-based design method, which could significantly reduce the difficulty of development. The comparison with the CPU solution results proves that FPGA has a significant acceleration effect on the solution of MPC through the method.
Research limitations implications
Due to the limitation of practical conditions, this paper cannot carry out a hardware-in-the-loop experiment for the time being, instead of an open-loop experiment.
Originality value
This paper proposes a new design method to deploy the MPC algorithm to the FPGA, reducing the development difficulty of the algorithm implementation on FPGA. It greatly facilitates researchers in the field of autonomous driving to carry out FPGA algorithm hardware acceleration research.
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