• Journal of the Korea Academia-Industrial cooperation Society
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• v.7 no.3
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• pp.338-343
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• 2006

In this paper, design of current and speed controller for DC motor drive system using dSPACE 1104 system is introduced. Current and speed controller is designed and implemented using MATLAB/SIMULINK program simply and easily, and speed control response of DC motor can be advanced. Current and speed control of DC motor is carried in DSP control board using dSPACE system. Speed feedback is processed through QEP using pulse encorder as speed sensor, and current feedback is processed through A/D converter using hall sensor as current sensor. Controller is designed to PI current controler and PI speed controller. Current and speed response is verified through simulations and experiments.

• Proceedings of the KIEE Conference
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• 1994.07a
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• pp.337-341
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• 1994

This paper describes an effort to develop a simulator of Active Power Filter (APF) by three dimentional(3-D) space current co-ordinate. System current is represented by 3-D vector composed of three current components - active, reactive and distorted. %THD (%Total Harmonics Distortion) can be converted to height-angle of system current vector and power factor can be defined on 3-D space current co-ordinate without loss of generality. Current of APF and power system can be analyzed by 3-D visualization of current vector trajectory. So, the computer simulation results show that the proposed method by 3-D space current co-ordinate make up for disadvantages of performance evaluation on time / frequency domain.

• Journal of Power Electronics
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• v.15 no.2
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• pp.497-503
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• 2015

This paper analyses the harmonic pollution to power grids caused by several high-power rectifiers, summarizes the requirements for rectifiers in suppressing grid-side current harmonics and optimizes a new-type of current source PWM rectifier with a hybrid switch. The rectifier with a hybrid switch boasts significant current characteristics and cost advantages in the high-power area. To further enhance the working frequency of the current source rectifier with a hybrid switch for suppressing grid-side harmonics and reducing the inductance size, this paper proposes an optimal control strategy based on space vector. It also verifies that the optimal control strategy based on space vector can reduce the total harmonic distortion of the grid-side current of the rectifier with a hybrid switch via circuit simulation and experimental results.

• Journal of the Korean housing association
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• v.17 no.4
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• pp.93-100
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• 2006

The purpose of the study was to analyze the appropriateness of space in multi-family housing by examining the current conditions of space, space norms and deficits, satisfaction with and needs for the spaces of individual rooms. The data came from the survey with 412 households living in Haeundae New Town, Busan and were analyzed with descriptive statistics. The appropriateness of space were mainly investigated in terms of housing size, number of bedrooms, and number of bathrooms. In terms of current space conditions, the highest portion of the households live in apartments with $20\sim30s$ pyong, 3 bedrooms, and 2 bathrooms. It was found that the space norms included housing with $30\sim40s$ pyong, 3 bedrooms, and 2 bathrooms. Households in current study tended to have some space deficits, especially in housing size and number or bathrooms. In general, the satisfaction with the current space of individual rooms were generally low except living room and master bedroom. It was also found that the households were more likely to make the second biggest bedroom bigger than now. The stages of family life cycle has significant effects on needs for the spaces of several rooms, such as dining room, room2, and room3.

• Journal of the Korean Society of Clothing and Textiles
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• v.33 no.4
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• pp.644-654
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• 2009

The purpose of this study is to analyze the characteristics of current fashion illustrations within the framework of Multi-space method. Multi-space means being piled up one moment & space on others, and being amassed in a scene. This method is related with Dadaism, Surrealism and Postmodernism, and also influences on the current fashion illustration. In this study, the types of Multi-space method could be classified into 4 types; Repetitive Time Mixture in Multi-space, Juxtaposed Time Mixture in Multi-space, Reiterated Space Mixture in Multi-space, Projected Space Mixture in Multi-space. The characteristics of Multi-space were analyzed and the results are as followed. The distinctive methods for Time Mixture in Multi-space are repetition and juxtaposition in a scene. Time Mixture in Multi-space can make the nonlinear narration and unreal illusory space in fashion illustrations more effectively. Reiterated Space Mixture in Multi-space can be related with the heterogeneous, surrealistic illusions in current fashion illustrations. Projected Space Mixture in Multi-space can be characterized into inter-penetration. It can derive spectators to mix the projected & transparent images in a scene for their own imaginary stories. The final imagination can be made differently according to the personal experiences of spectators.

• The Journal of Sustainable Design and Educational Environment Research
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• v.12 no.3
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• pp.11-25
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• 2013

This study aims on finding a direction of desirable space organization of future elementary school in Korea by analyzing current status of space organization of elementary school in Japan. In this study comparison and analysis of curriculum of Korea and Japan, facility standards on national level and standards of national subsidy, current status of number of schools and students, transition of changes in facility area of elementary school for last 10 years are included. In Korea and Japan each 7 elementary schools which were constructed after 2007 and are good in space organization and school planning are selected. The comparison and analysis of satisfaction level on physical educational conditions and facilities such as current status of space organization and how to use them are conducted in this study. The contents of analyzing space organization are 'entry and placement, outdoor space', 'space program' and 'phase structure and organization of unit space'.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.41 no.7
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• pp.742-752
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• 1992

In this paper, a space vector concept is generalized for PWM(pulse-width modulated) inverters and PWM rectifiers with current link and voltage link respectively. Through representing three-phase variables as a space vector, we propose space vector modulations for PWM voltage and current source inverters, and PWM rectifiers with current link and voltage link. For these types, switching states of the switches are systematically analyzed from tables. It is shown in three-phase PWM rectifiers that power factor of the line current and output dc voltage can be controlled arbitrarily. The PWM rectifier with current link is also given as an example system.

• Journal of Astronomy and Space Sciences
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• v.36 no.1
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• pp.1-9
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• 2019

In this paper we present analysis of current density when the Cluster spacecraft pass the nightside auroral region at about $4-5R_E$ from the center of Earth. The analysis is made when the inter-spacecraft separation is within 200 km, which allows all four spacecraft to be situated inside the same current sheet. On 22 February 2002, two field-aligned current (FAC) events were observed in both the southern and the northern hemispheres. The FACs were calculated with magnetic field data obtained by the four spacecraft using the Curlometer method. The scales of the FACs along the spacecraft trajectory and the magnitudes were hundreds of kilometers and tens of $nA/m^2$, respectively, and both events were mapped to the auroral region in the ionosphere. We also examined reliability of the results with some parameters, and found that our results are adequately comparable with other studies. Nevertheless, some limitations that decrease the accuracy of current estimation exist.

• Proceeding of Spring/Autumn Annual Conference of KHA
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• 2006.11a
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• pp.144-148
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• 2006

Kitchen space is one of the most dangerous places for the elderly. Modification of kitchen space for improving safety and independence for older residents is very important factor for aging -in-place. The purpose of this study wes to identify the current situation and modification of kitchen space by elderly-headed household. The sample included 108 respondents over the age 65 who consisted of elderly-couple or single person household with homeownership in Seoul. The data were analyzed by descriptive statistics. Based on the findings of the study, the present incidence and recognition of future need in kitchen modification were identified. Changes in kitchen space made tended to be nonstructural or relatively inexpensive items. In conclusion, this study suggests several ideas for improving current physical problems of kitchen space to support daily living of older residents.

• Journal of the Korean housing association
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• v.18 no.2
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• pp.49-58
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• 2007

Kitchen space is one of the most dangerous places for the elderly. Modifications of kitchen space for improving safety and independence for older residents are very important factor for aging in place. The purpose of this study was to identify the current situations and modifications of kitchen space by elderly-headed households. The sample included 108 respondents over the age 65 who consisted of elderly-couple or single person household with homeownership in Seoul. The data were analyzed by descriptive statistics. Based on the findings of the study, the present incidence and recognition of future need in kitchen modifications were identified. Changes made in kitchen space tended to be nonstructural or relatively inexpensive items. In conclusion, this study suggests several ideas for improving current physical problems of kitchen space to support safe and independent daily living of older residents.