• Journal of Electrical Engineering and Technology
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• v.11 no.4
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• pp.931-938
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• 2016

Application of vector control scheme for consumer products is enlarging to improve control performance. For the field-oriented control, accurate position detection is essential and generally requires expensive sensors. On the other hand, cost-reduction is important in home appliances, so that binary-type Hall-effect sensors are commonly used rather than using an expensive sensor such as an encoder. The control performance is directly influenced by the accuracy of the position information, and there exist non-uniformities related to Hall sensors in electrical and mechanical aspects, which result in distorted position information. Therefore, to get high-precision position information from low-resolution Hall sensors, this paper proposes a new position estimator consisting of a Kalman filter and feedforward compensation scheme, which generates a linearly changing position signal. The efficacy of the proposed scheme is verified by simulation and experimental results carried out with a 48-pole permanent magnet motor.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.1972-1973
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• 2007

A field-oriented UHF system for on-line PD monitoring of transformers is designed, which has been installed inside the oil tank of a transformer. This system has successfully captured long intermittent discharge signals that hadn't been detected through conventional techniques, and solved the problem successfully. The results demonstrate that UHF technique has great advantages for on-line PD monitoring of transformers. By adopting the peak detection technique, it becomes easy and effective for the transplantation of the phase-resolved pattern recognition technique from conventional method to UHF method, and then to realize continuous on-line monitoring, source characterization and trending analysis.

• MALSORI
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• no.60
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• pp.125-144
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• 2006

W3C announced a standard software architecture for multimodal context-aware middleware that emphasizes modularity and separates structure, contents, and presentation. We implemented a distributed multimodal interface system followed the W3C architecture, based on SCXML. SCXML uses parallel states to invoke both XHTML and VoiceXML contents as well as to gather composite or sequential multimodal inputs through man-machine interactions. We also hire Delivery Context Interface(DCI) module and an external service bundle enabling middleware to support context-awareness services for real world environments. The provision of personalized user interfaces for mobile devices is expected to be used for different devices with a wide variety of capabilities and interaction modalities. We demonstrated the implemented middleware could maintain multimodal scenarios in a clear, concise and consistent manner by some experiments.

• Transactions of Materials Processing
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• v.3 no.3
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• pp.291-301
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• 1994

In the simultaneous forward-backward extrusion the effects of some process variables including area reduction, stroke advance, materials(Al 2024 and commercial pure copper) on the extrusion load, plastic flow and height ratio of upper to lower extruded parts are experimentally investigated and analyzed. Grid-marking technique is employed to visualize the plastic flow. The influence of using split and original specimen on the extrusion load and height ratio is evaluated by experiments. Experimental results show that the plastic flow if oriented to the part of lower area reduction in the begining but it is usually variated during the overall process. The configurations of plastic deformation and plastic flow are dependent on the working materials and the lubricational conditions.

• Journal of Information Technology Services
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• v.2 no.1
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• pp.123-133
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• 2003

Because of rapid evolution of software technique, numerous software professionals have been concerned with component based development methodologies. However, it is hard to find out a systematic technique for the selection of COTS (Commercial Off The Shelf) component in consumer position. Up to date, the major of component quality evaluation is object-oriented metric based evaluation methodology. But this paper present four step process and evaluation criteria based on MCDM (Multiple Criteria Decision Making) technique for optimal COTS component selection in consumer position. Weconsidered funtionality, efficiency, usability based on ISO/IEC 9126 for quality measurement and executed practical analysis about commercial EJB component in internet. This paper show that the proposed selection technique is applicable to optimal COTS component selection.

• Journal of Information Technology Services
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• v.7 no.4
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• pp.61-86
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• 2008

Korea 5MBA(Small and Medium Business Administration) is operating SMEs Policy Information System called SPi-1357 as a part of electronic government business, G4B. SPi-1357 system is offering tailor made policy information to a nation through on-off line system. In this paper, I provide the offering status of policy information, the status of SPi-1357 system, political results of SPi-1357 system, comparison with other country's policy information system, and the development direction of SPi-1357 system. Until now, most Policy Information Systems documents have focused on policy maker but the focus of this paper is functionally oriented SMEs.

• Journal of Information Technology Services
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• v.7 no.4
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• pp.287-300
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• 2008

Our Study aims to examine, from a critical perspective, recent approaches to the definition of services, Studies that deal with the question of how to characterize services offer three types of response. The first approach developed by classical economists proposes to use technical criteria (immateriality, non-separability between consumption and production, non-storage, heterogeneity) as foundation for a specific definition of services. The second, which is today most widely cited definition, that of Peter Hill proposes an institutional or a relation-oriented definition which emphasizes service triangle. Finally, the work of Gadrey, which investigates the impact of new technologies on service activities, offers a new general definition of services that is compatible with the existence of several demand rationales.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.8
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• pp.1472-1477
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• 2007

Users are offered by the multimedia service of various information on current information-oriented society. The digitize became essential that process of various data is not to selected. Also, Filter technology is required to use the lacking frequency resources efficiently. This paper designs FIR digital band-pass filter of the voice band by narrow band pass filter md verify the characteristics of filter to use by the DSP practice SET.

• Computers and Concrete
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• v.18 no.2
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• pp.201-214
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• 2016

In this paper, a multilaminate based model have been developed and presented to predict the strain hardening behavior of rock. In this multilaminate model, the stress-strain behavior of a material is obtained by integrating the mechanical response of an infinite number of predefined oriented planes passing through a material point. Essential features such as the variable deformations hypothesis and multilaminate model are discussed. The methodology to be discussed here is modeling of strains on the 13 laminates passing through a point in each loading step. Upon the presented methodology, more attention has been given to hardening in non-linear behaviour of rock in going from the peak to residual strengths. The predictions of the derived stress-strain model are compared to experimental results for marble, sandstone and dense Cambria sand. The comparisons demonstrate the ability of this model to reproduce accurately the mechanical behavior of rocks.

• Proceedings of the Korea Society for Simulation Conference
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• 2003.11a
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• pp.59-65
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• 2003

In order to reduce the cost of software maintenance including software modification, we suggest the object oriented program with checking the version of application program using the Java language and the technique of executing the downloaded application program via network using the application manager. In order to change the traditional scheduler to the application manager we have adopted the Xlet concept in the nuclear fields using the network. In usual Xlet means a Java application that runs on the digital television receiver. The Java TV Application Program Interface(API) defines an application model called the Xlet application lifecycle. Java applications that use this lifecycle model are called Xlets. The Xlet application lifecycle is compatible with the existing application environment and virtual machine technology. The Xlet application lifecycle model defines the dialog(protocol) between an Xlet and its environment