• Journal of Power Electronics
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• v.17 no.1
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• pp.76-87
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• 2017

Finite-set predictive current control (FS-PCC) is advantageous for power converters due to its high dynamic performance and has received increasing interest in multilevel inverters. Among multilevel inverter topologies, the cascaded H-bridge (CHB) inverter is popular and mature in the industry. However, a main drawback of FS-PCC is its large computational burden, especially for the application of CHB inverters. In this paper, an FS-PCC method based on a deadbeat solution for three-phase zero-common-mode-voltage CHB inverters is proposed. In the proposed method, an inverse model of the load is utilized to calculate the reference voltage based on the reference current. In addition, a cost function is directly expressed in the terms of the voltage errors. An optimal control actuation is selected by minimizing the cost function. In the proposed method, only three instead of all of the control actuations are used for the calculations in one sampling period. This leads to a significant reduction in computations. The proposed method is tested on a three-phase 5-level CHB inverter. Simulation and experimental results show a very similar and comparable control performance from the proposed method compared with the traditional FS-PCC method which evaluates the cost function for all of the control actuations.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.32 no.5
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• pp.67-71
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• 2000

The history of the paper industry has shown a strong technological evolution which has been an essential factor in achieving low cost, high quality paper products and in sustaining the strength of the industry. In the last decades paper machine development has been rapid. This has helped to establish paper as a "low cost" material. In future, the pressure from the competing media will only accelerate the technological efforts to improve cost and functional'||'&'||'not;ity of paper. In addition, in the future, technological advances will be combined with innovation in busi'||'&'||'not;ness concepts. Certain production methods are likely to be developed which will distribute current process stages outside the paper mill. Papermakers can begin to reduce their invest'||'&'||'not;ment risk by subcontracting large-scale base paper production but taking responsibility for the higher value finishing process stages. Finishing will be more closely integrated with the final use. The role of technology supplier to the paper industry will naturally evolve to reflect all these changes. Metso is already actively collaborating downstream in the different paper-related business chains. This collaboration will be crucial for implementation of new business and technology innovations in P'||'&'||'P industry and Metso will certainly benefit from its catalyst role in this transition.

• Journal of Distribution Science
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• v.20 no.9
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• pp.11-21
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• 2022

Purpose: Many concerns have appeared in banking sector in the digital era and one of them is that technology development will increase operation costs of banks. Motivated by this issue, our study aims to explore the effect of technological and digital investments on cost-effectiveness of banking operation. Research design, data and methodology: To reach a clear answer, we use the data of 12 commercial banks spanning from 2011 to 2020 in Vietnam and employ multivariate regression analysis as well as perform various robustness tests. Results: Our regression result indicates that the adverse effect of technological spending on cost-effective operation. This finding still remains unchanged when we conduct different robust tests. Also, we find that this negative impact becomes more evident in large banks than in small ones. Conclusions: The paper provides one of the most important empirical results for mangers and policy-makers in banking sphere, especially in Vietnam where regulators have been calling for continuously investing into technological innovation in banks. The evidence confirms that banks should carefully consider an increase in spending on distribution information and communication technologies when constructing business strategies related to expanding digitalization. Our research is also useful for countries having similar financial structure to Vietnam.

• Journal of the Korean Operations Research and Management Science Society
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• v.3 no.1
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• pp.57-67
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• 1978

This paper reviews various models of technological innovations at different levels: project level and productive segment level. Firstly, it examines a number of significant factors influencing the success and failure of technological innovation at project level. Specifically, the role and characteristics of technical information for the success of innovation is analyzed. Secondly, the paper discusses in detail the relationship between technological innovation and the evolution of a firm. Product and process innovations are analyzed in accordance with a three stage model; the stages are performance maximizing (uncoordinated), sales maximizing (segmental) and cost minimizing (systemic). Various implications of the model are presented in terms of the business policy variables such as diversification, standardization, productivity improvement, marketing, etc. The applicability of the model to a developing country is sought and a few suggestions to develop new model of technological innovations in LDC are discussed.

• Korean System Dynamics Review
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• v.1 no.2
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• pp.33-60
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• 2000

This study aims to conceptually identify the circular causal-relationship which is structured between downsizing and technological innovation in organization. First, through the literature review concerning downsizing and (technological) innovations, we have outlined the conceptual building blocks and research boundaries in this field. Second, we used system thinking method to accomplish our research purpose. The research findings are as follows. First, the promotion of financial resources by downsizing have trade-off relations that have negative of effects in short terms, but positive effects in long time. Second, workforce reduction by downsizing usually has negative influence on employees. Third, capital reduction by downsizing generates not only the climates of cost-cut but also the fact that although the climates may increase economic performance in short terms, it may interrupt technological innovations in long terms. In conclusion, this theses suggests that the relationship of downsizing and technological innovations have complex causal and feedback structures. Therefore, the results of this thesis propose that the argument or practices of downsizing with partial emphasis is very dangerous. Finally some limitations are also discussed.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.12
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• pp.5500-5508
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• 2011

The purpose of this study is to find out the policy implications regarding the EU FP and EUREKA which consist of the main parts in the midst of the international technological cooperation with EU region that our government is implementing. This study consists of five chapters in all. The present situations of the international technological cooperation in EU region were investigated in chapter two. Successively, the theoretical background regarding the policy implications for the international technological cooperation in EU region was provided in chapter three. As the theories establishing the bases at this point, there are network and transaction cost theory. The research methods were provided in chapter four, and through the policy case study of our government's international technological cooperation in EU region, the theoretical establishment developed in chapter three was carried out in chapter five. Subsequently, conclusions and suggestions were drawn in chapter six.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.16 no.2
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• pp.23-40
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• 2013

The natural environment restoration industry has been newly included in the environment area of engineering technology. Accordingly, the enactment of a standard of estimate for determining the 'Cost plus Fixed Fee' method has become necessary for the implementation and vitalization of natural environment restoration projects. The purpose of this study is to determine the standards for which the prices for engineering projects are calculated with respect to the enactment of an engineering project standard of estimate in the natural environment restoration field. These include the scope of the technological work, standard area, manpower requirements by technical grade that are necessary for carrying out the technological tasks. Relevant laws and regulations, systems and precedent case studies were investigated and analyzed to establish a price calculation standard. The overall results of the analysis were used and applied to questionnaires, public hearings, and expert delphi techniques. The study showed the following results： The scope of the technological work was categorized into 'Biotopes', 'Eco-corridors' and 'Ecological restoration'. The standard area was set up as $1,000m^2$ for 'Biotopes' and $5,000m^2$ for 'Eco-corridors' and 'Ecological restoration'. The manpower requirements by technical grade that are necessary for carrying out the technological tasks were determined. The suitability of the costs, standard area, manpower requirements by technical grade of ordered engineering projects that are determined by applying the standard of estimate for natural environment restoration that may be enacted pursuant to this study may be effectively investigated and analyzed. Moreover, further studies on the calculation of standard prices that can ensure the stability of natural environment restoration projects will be necessary.

• Journal of Korean Society of Forest Science
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• v.95 no.3
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• pp.268-273
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• 2006

This study analyzed the technological change of Korean sawmill industry affected by change of factor price. An aggregate cost function has been estimated to analyze the technological change in Korean sawmill industry between 1970 and 2003 to the technical bias and scale effect. There was substitution among labour, capital, and material, especially in more elastic relation between labour and capital. In addition, domestic sawmill industry was progressed into structure which is biased to labour saving, and capital and material using because of increase of labour price. Since Korean sawmill industry's technology still exhibits an increasing returns to the scale, the large amount of investment has contributed to productivity growth, and the future productivity growth continually depend on the scale effect for some time.

• Journal of Power Electronics
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• v.12 no.5
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• pp.758-768
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• 2012

This paper presents the modeling and position-sensorless vector control of a dual-airgap axial flux permanent magnet (AFPM) machine optimized for use in flywheel energy storage system (FESS) applications. The proposed AFPM machine has two sets of three-phase stator windings but requires only a single power converter to control both the electromagnetic torque and the axial levitation force. The proper controllability of the latter is crucial as it can be utilized to minimize the vertical bearing stress to improve the efficiency of the FESS. The method for controlling both the speed and axial displacement of the machine is discussed. An inherent speed sensorless observer is also proposed for speed estimation. The proposed observer eliminates the rotary encoder, which in turn reduces the overall weight and cost of the system while improving its reliability. The effectiveness of the proposed control scheme has been verified by simulations and experiments on a prototype machine.

• Journal of Information Technology Services
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• v.13 no.4
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• pp.169-188
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• 2014

Recently the complexity and difficulty of the IT projects are increasing due to technological and environmental risks, resulting in the adoption of PMO(Project Management Office) onto IT project management practices, including public area projects. For example, the Korean government regulated the application of PMO onto large scale public IT projects. However, since there has been no reliable method to estimate the cost to execute PMOs, a PMO cost evaluation model to support the budget and cost planning of PMO projects is required. Thus, the purpose of this research is to develop a systematic cost evaluation model for PMO projects. We identified the dimensions that determine the PMO execution cost to be the scale of the subject project, the technical difficulty level of the subject project, and the tasks to be executed in the PMO project. Based on the determinants, the PMO execution cost model were developed from historical data and experts opinion. Upon verification, the validity of the developed model has high level of consistency compared with their experiences of real PMO project costs.