• Journal of Power Electronics
• /
• v.11 no.1
• /
• pp.105-111
• /
• 2011

By having accurate knowledge of the magnetic field distribution and the thrust calculation in linear synchronous motors, assessing the performance and optimization of the motor design are possible. In this paper, after carrying out a performance analysis of a single-sided wound secondary linear synchronous motor by varying the motor design parameters in a layer model and a d-q model, machine single- and multi-objective design optimizations are carried out to improve the thrust density of the motor based on the motor weight and the motor efficiency multiplied by its power factor by defining various objective functions including a flexible objective function. A genetic algorithm is employed to search for the optimal design. The results confirm that an overall improvement in the thrust mean, efficiency multiplied by the power factor, and thrust to the motor weight ratio are obtained. Several design conclusions are drawn from the motor analysis and the design optimization. Finally, a finite element analysis is employed to evaluate the effectiveness of the employed machine models and the proposed optimization method.

• Journal of international Conference on Electrical Machines and Systems
• /
• v.2 no.3
• /
• pp.349-355
• /
• 2013

This paper presents the multi-objective optimisation of an Inductive Coupled Power Transfer (ICPT) device. A setup as complicated as the one at hand in this paper is extremely hard to model analytically. To acquire some knowledge about the influence of the geometric factors, a sensitivity analysis is first performed using design of experiment (DoE) and finite-element modelling (FEM). It allows validating that the choice of the free factors is relevant. This being done, the optimisation itself is performed using a genetic algorithm (GA), with two objectives and a strict functioning constraint.

• Earthquakes and Structures
• /
• v.13 no.1
• /
• pp.29-38
• /
• 2017

Stone masonry is one of the oldest construction types due to the natural and free availability of stones and the relatively easy construction. Since stone masonry is brittle, it is also very vulnerable and in the case of earthquakes damage, collapses and causalities are very likely to occur, as it has been seen during the last Italian earthquake in Amatrice in 2016. In the recent years, some researchers have performed experimental tests to improve the knowledge of the behaviour of stone masonry. Concurrently, there is the need to reproduce the seismic behaviour of these structures by numerical approaches, also in consideration of the high cost of experimental tests. In this work, an alternative simplified procedure to numerically reproduce the diagonal compression and shear compression tests on a rubble stone masonry is proposed within the finite element method. The proposed procedure represents the stone units as rigid bodies and the mortar as a plastic material with compression and tension inelastic behaviour calibrated based on parametric studies. The validation of the proposed model was verified by comparison with experimental data. The advantage of this simplified methodology is the use of a limited number of degrees of freedom which allows the reduction of the computational time, which leaves the possibility to carry out parametric studies that consider different wall configurations.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
• /
• v.1
• /
• pp.259-264
• /
• 2006

It is well known that the uncertainty of the covariance parameters of the process noise (Q) and the observation errors (R) has a significant impact on Kalman filtering performance. Q and R influence the weight that the filter applies between the existing process information and the latest measurements. Errors in any of them may result in the filter being suboptimal or even cause it to diverge. The conventional way of determining Q and R requires good a priori knowledge of the process noises and measurement errors, which normally comes from intensive empirical analysis. Many adaptive methods have been developed to overcome the conventional Kalman filter's limitations. Starting from covariance matching principles, an innovative adaptive process noise scaling algorithm has been proposed in this paper. Without artificial or empirical parameters to be set, the proposed adaptive mechanism drives the filter autonomously to the optimal mode. The proposed algorithm has been tested using road test data, showing significant improvements to filtering performance.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
• /
• 2009.05a
• /
• pp.416-419
• /
• 2009

The widely used control theory based design of PI family controllers fails to perform satisfactorily under-parameter variation, nonlinear or load disturbance. In high performance applications, it is useful to automatically extract the complex relation that represent the drive behaviour. The use of loaming through example algorithms can be a powerful tool for automatic modelling variable speed drives. They can automatically extract a functional relationship representative of the drive behavior. These methods present some advantages over the classical ones since they do not rely on the precise knowledge of mathematical models and parameters. The paper proposes high performance speed and current control of synchronous reluctance motor(SynRM) drive using adaptive loaming mechanism-fuzzy neural network (ALM-FNN) and fuzzy logic control(FLC) controller. The proposed controller is developed to ensure accurate speed and current control of SynRM drive under system disturbances and estimation of speed using artificial neural network(ANN) controller. Also, this paper proposes the analysis results to verify the effectiveness of the ALM-FNN and ANN controller.

• The Mathematical Education
• /
• v.54 no.1
• /
• pp.65-81
• /
• 2015

The purpose of this study is to investigate the international trends of how the core competencies are reflected in mathematics curriculum, and to find the implications for the revision of Korean mathematics curriculum. For this purpose, the curriculum of the 9 countries including the U.S., Canada(Ontario), England, Australia, Poland, Singapore, China, Taiwan, and Hong Kong were thoroughly reviewed. It was found that a variety of core competencies were reflected in mathematics curricula in the 9 countries such as problem solving, reasoning, communication, mathematical knowledge and skills, selection and use of tools, critical thinking, connection, modelling, application of strategies, mathematical thinking, representation, creativity, utilization of information, and reflection etc. Especially the four most common core competencies (problem solving, reasoning, communication, and creativity) were further analyzed to identify their sub components. Consequently, it was recommended that new mathematics curriculum should consider reflecting various core competencies beyond problem solving, reasoning, and communication, and these core competencies are supposed to combine with mathematics contents to increase their feasibility. Finally considering the fact that software education is getting greater attention in the new curriculum, it is necessary to incorporate computational thinking into mathematics curriculum.

• Structural Engineering and Mechanics
• /
• v.71 no.3
• /
• pp.233-244
• /
• 2019

Steel jacketing technique is a retrofitting method often employed for static and seismic strengthening of existing reinforced concrete columns. When no continuity is given to angle chords as they cross the floor, the jacket is considered "indirectly loaded", which means that the load acting on the column is transferred partially to the external jacket through interface shear stresses. The evaluation of load transfer mechanism between core and jacket is not straightforward to be modeled, due to the absence of knowledge of a proper constitutive law of the concrete-to-steel interface and to the difficulties in taking into account the mechanical nonlinearities of materials. This paper presents an incremental analytical/numerical approach for evaluating the compressive response of RC columns strengthened with indirectly loaded jackets. The approach allows calculating shear stresses at the interface between core and jacket and predicting the axial capacity of retrofitted columns. A proper constitutive law is proposed for modelling the interaction between the steel and the concrete. Based on plasticity rules and the non-linear behaviour of materials, the column is divided into portions. After a detailed parametric analysis, comparisons are finally made by theoretical predictions and experimental results available in the literature, showing a good agreement.

• Journal of Distribution Science
• /
• v.20 no.12
• /
• pp.59-69
• /
• 2022

Purpose: The purpose of this research is to identify and design a model for the integration between marketing and supply chain management (SCM) of technopreneurship-based souvenirs MSMEs to fulfil customer value creation. Research design, data and methodology: This research method uses the system development life cycle method. This study draws its insights and conclusions from a literature review in several fields followed by an interactive research approach that helps identify, validate, and implement a theoretical framework so that the modelling results can be adopted in applicative manner for souvenir MSMEs. Result: Implementing the "G-ASPOO-L" supply chain management integration model based on technopreneruship to fulfil value creation in the 5.0 society era created three perspectives: an inter-functional perspective, a process perspective, and an integrated business concept perspective. The supply chain management involves enterprise integration, strategic customer integration, strategic supplier integration, and marketing strategy integration. Conclusion: The proposed model framework leads to managerial problems of supply chain management strategy, which urgently requires an interaction approach that challenges the traditional view of demand creation and implementation of supply chain management to fulfil value creation. This research leverages existing knowledge and advances our understanding of the strategic integration issues companies face in digital-based competition.

• The Journal of Asian Finance, Economics and Business
• /
• v.8 no.4
• /
• pp.307-315
• /
• 2021

The study aims to investigate the relationship between innovation activities and business process performance in higher education institution (hereinafter referred to as "HEI") context. The data was collected using a survey and later analyzed through Partial Least Squares Structural Equation Modelling (PLSSEM) and SmartPLS software. A total of 50 questionnaires were submitted from respondents representing vocational study program management located in Makassar, Indonesia. The findings show that two hypotheses discussed in this study fit the empirical data. Specifically, the results show that there is a positive relationship between innovation activities and business process performance, involving two types of innovation activities, which are exploration activities and exploitation activities, within HEIs. Explorative activity is firmly related to exploitative activity, which furthermore links to business process performance within the HEIs observed. The results confirm that exploration activity can stimulate and lead the HEIs management to generate exploitation activity. For instance, capabilities to absorb knowledge from the external institution may lead this institution to generate advanced academic processes, as well as more efficient and effective managerial processes. The study also signifies ambidexterity capacity, suggesting that it may lead HEIs management to formulate proper strategies in achieving better performance and gaining competitive advantage.

• Smart Structures and Systems
• /
• v.30 no.1
• /
• pp.35-47
• /
• 2022

Data-driven engineering is crucial for information delivery between design, fabrication, assembly, and maintenance of prefabricated structures. Design for manufacturing and assembly (DfMA) is a critical methodology for prefabricated bridge structures. In this study, a novel concept of digital engineering model that combined existing knowledge of DfMA with object-oriented parametric modeling technologies was developed. Three-dimensional (3D) geometry models and their data models for each phase of a construction project were defined for information delivery. Digital design models were used for conceptual design, including aesthetic consideration and possible variation during fabrication and assembly. The seismic performance of a bridge pier was evaluated by linking the design parameters to the calculated moment-curvature curves. Control parameters were selected to consider the tolerance control and revision of the digital models. Digitalized fabrication of the prefabricated members was realized using the digital fabrication model with G-code for a concrete printer or a robot. The fabrication error was evaluated and the design digital models were updated. The revised fabrication models were used in the preassembly simulation to guarantee constructability. For the maintenance of the bridge, the as-built information was defined for the prefabricated bridge piers. The results of this process revealed that data-driven information delivery is crucial for lifecycle management of prefabricated bridge piers.