• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.25 no.4
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• pp.124-134
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• 2011

A new dead time compensation scheme that can exactly estimate the dead time and inverter nonlinearity under parameter variations is proposed for a PWM inverter-fed PMSM drive. The proposed scheme uses the fact that the sixth harmonic component in total disturbance estimated under the presence of various uncertainties is mainly caused by the dead time and inverter nonlinearity. The total disturbance due to the parameter variations as well as the dead time and inverter nonlinearity is estimated by the adaptive scheme. The sixth harmonic component is extracted from this total disturbance through harmonic analysis. The obtained sixth harmonic is processed by the PI controller to estimate the disturbance caused by the dead time and inverter nonlinearity in the stationary reference frame. The effectiveness of the proposed scheme is verified. Without requiring an additional hardware, the proposed scheme can effectively compensate the dead time and inverter nonlinearity even under the parameter variations.

• IE interfaces
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• v.13 no.1
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• pp.141-146
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• 2000

Through an on-line software distribution, a user can get the software easily using Internet. As purchase, receipt and installation of software are executed via on-line batch process the time for software purchase and installation can be reduced. In this paper, we describe technologies for on-line software distribution and propose a secure software distribution and installation protocol for electronic commerce.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.26 no.1
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• pp.29-37
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• 2012

A simple and effective dead time compensation scheme for a PWM inverter-fed permanent magnet synchronous motor (PMSM) drive using the model reference adaptive control (MRAC) and coordinate transformation is presented. The basic concept is to first transform a time-varying disturbance caused by the dead time and inverter nonlinearity into unknown constant or slowly-varying one by the coordinate transformation, and then use the MRAC design technique to estimate this parameter in the stationary reference frame. Since the MRAC scheme is a suitable way of estimating such a parameter, the control performance can be significantly improved as compared with the conventional observer-based method tracking time-varying parameters. In the proposed scheme, the disturbance voltage caused by the dead time is effectively estimated and compensated by on-line basis without any additional circuits nor existing disadvantages as in the conventional methods. The asymptotic stability is proved and the effectiveness of the proposed scheme is verified.

• Korean Institute of Interior Design Journal
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• no.26
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• pp.104-111
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• 2001

This study deals with the expressive characteristics of Installation Art and their applicability to environmental design, and as such, aims to specify a artistic methods from the contemporary art. What Installation Art is search of in their works is "the state of relationships" which is "to replace the concept of form with that of structure, and the concept of space with that of the environment" that is, the terms of relations in the overall environment of time and space. Installation Art essentially relies on a multiplicity of forms and attitudes leading to projects which positively make use of "spatial-temporal process" to reaffirm and "problematise" their open-endedness manifest in complex contextuality and shifting temporality. This study presents a new interpretation of spatial-temporal dimension, site-specificity, and intermedia art that we find in Installation Art and tries to combine that new artistic insight a with environmental design to provide a basis for integrated art. This study places a great emphasis on the interdisciplinary approaches to the environment we inhabit, which I hope will contribute to generating a greater number of creative possibilities for environmental design.

• Journal of The Korean Society of Agricultural Engineers
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• v.52 no.3
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• pp.113-120
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• 2010

Reduction factor for installation damage required to calculate design strength of geogrid used in MSEW(mechanically stabilized earth wall) design is usually obtained in the field test simulating real construction condition. However, damages occurred in geogrid during backfill work are influenced by many factors such as polymer types, unit weight per area, backfill construction method and gradation of backfill material and field test considering these factors demand lots of time and costs. In this study, factors affecting installation damage are analyzed and empirical method to evaluate reduction factor for installation damage using maximum particle size in backfill material is suggested.

• Journal of Multimedia Information System
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• v.9 no.1
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• pp.43-50
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• 2022

As the discourse on Anthropocene grows, this exploratory research investigates the interrelationship and interconnectivity between humanity and technology by analyzing a sound art installation created by the author. Crying Sea is a sound installation that uses plastic wastes collected from the shore to create symbolic narratives and artistic experience connecting humans, objects, and nature through interactive digital technology. In this installation, the audiences are guided to walk over the wastes, and the sounds created by the footsteps are recorded in real-time, which then are distorted and amplified into disturbing sounds through speakers filling up the room. In analyzing this artwork, three theories from technological, philosophical, and ecological backgrounds were used; specifically, Bernard Stiegler's pharmakon theory, Dona Haraway's cyborg manifesto, and Timothy Morton's dark ecology theory. A common factor revealed from all three theories by analyzing the Crying Sea is that humans, technologies, and all other entities within nature are interconnected and resonated. The awareness of this recursive relationship allows us to consider sustainable balancing.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 1999.11a
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• pp.76-79
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• 1999

This paper describes real power difference continuous and on/off operation of ballast for fluorescent lamps. We tested ballasts for fluorescent lamps, such that glow stater ballast, rapid stating ballast, and electronic ballast. We measured consumed real power. Input voltage is A.C. 220V and ON time 8 is minutes, OFF time 2 is minutes.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2003.11a
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• pp.355-359
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• 2003

In this paper, an identification method for a first order dead time process is proposed. This method used the genetic algorithm for parameter identification of process. The proposed method gives a better identification result than the existing methods under step testing. The effectiveness of the identification method has been demonstrated through a number of simulation examples.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2003.11a
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• pp.97-102
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• 2003

Ground in must choose enough sectional area of conductor endurably in maximum fault current, fault duration time, maximum allowable temperature and have strong durability and life-time can bear enough from spontaneous corrosion or electrolytic corrosion and must choose material that problem does not exist electrically and mechanically when connection or junction. In this paper, modeled new ground wire size numerical formula, and examine and compare of modeled numerical formula and abroad regulation, and proved and analyzed validity of the new ground wire size computation method because do simulation to computer program.

• Journal of Fisheries and Marine Sciences Education
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• v.25 no.3
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• pp.733-742
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• 2013

The Korea has significant tidal current energy resources, but it is so hard to work underwater for tidal turbine installation. Therefore commercial diving work is very important for tidal current generator. Also, Jangjuk channel is vary famous as proper area to generate tidal current energy. Nevertheless, no one is studied about characteristics of commercial diving works with installation of tidal current generator. The purpose of this study is to introduce commercial diving with work types and investigate critical limits of diving working under the conditions, which are working only to minutes at slack tide during the neap tide. As the results, work types are five as like mooring installation, OMAS(Offshore Maintenance Access System), support structure installation, cable and turbine installation. Here, the original construction period is expected about 4 months, but the construction take 18 months to complete. The cause of extends construction period is insufficiency of researching tidal current conditions at the site and ignorance of slack tide which need to secure diving working time. Total diving working times are 110th during 18 months, the highest percentage of diving times is turbine installation about 43.6 %, and cable, mooring installation and support structure construction are 27.3 %, 15.5 %, 13.6 %, respectively. On the basis of this study, estimation of times of commercial diving is possible with work types of tidal current power, and has a significance as basic data to determining construction period.