• KIEAE Journal
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• v.10 no.1
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• pp.11-18
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• 2010

Permanent rental housing complex is subjected to both an increase in the crime rate due to its residential population structure and social, economic isolation for insecurd income of the residents. It should be considered that the densely populated area with low-income group of the city causing many problems related with the community. This study focused on the Man-soo 7 housing estate in Incheon with the area's average scale and ratio is made as an effort to include the residents who live in the permanent rental housing area among the members of the healthy community. The result of the research suggests the method of housing improvement to establish the successful support institution for self-sufficiency of the low income inhabitants analazying the demand of the residents through a survey categorized into resident support system, public workplace and inhabitant participation.

• Journal of the Korea Safety Management & Science
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• v.15 no.2
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• pp.151-159
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• 2013

This paper reviewed the relationship between internal marketing(management support, education, pay system, internal communication, employment security) and food safety climate(prevention, superior attitude, work condition), and the moderating effect of employment type(permanent or temporary employees) in food service company. Based on the responses from 304 responses, the results of hierarchical multiple regression analysis showed that 4 factors(management support, education, internal communication, employment security) effect positively on food safety climate(prevention, superior attitude, work condition). The positive effect of internal communication on superior attitude and work condition appeared to be more positive in permanent employees than in temporary employees. And the results of t-test analysis showed that permanent employees perceived more positively all internal marketing factors(management support, education, pay system, internal communication, employment security) and food safety climate(precaution, superior attitude, work condition) than temporary employees.

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.149-152
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• 2004

Speed and torque control of PMSM(Permanent Magnet Synchronous Motor) are usually achieved by using position and speed sensors which require additional mounting space, reduce the reliability in harsh environments and increase the cost of a motor. Therefore, many studies have been performed for the elimination of speed and position sensors. In this paper, a novel speed sensorless control of a permanent magnet synchronous motor based on SVMR(Support Vector Machine Regression) is presented. The SVM regression method is an algorithm that estimates an unknown mapping between a system's input and outputs, from the available data or training data. Two well-known different voltage model is necessary to estimate the speed of a PMSM. The validity and the usefulness of proposed algorithm are thoroughly verified through numerical simulation.

• Journal of Families and Better Life
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• v.25 no.5
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• pp.185-197
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• 2007

Permanent rental housing which is entirely financed by the Government is welfare housing for those who fall within the lowest income bracket. This type of housing is intended for use as rental housing on a long-term basis. At present, there are about 190,000 permanent rental housing units in Korea. The purpose of this study is to suggest the implications to improve the management and welfare service system of permanent rental housing. For this, qualitative data were collected by using the in-depth interview with staffs of community welfare center and management office of five permanent rental housing complexes and two times of advisory committee meeting with housing and social welfare experts. To analyze the data gathered in this study, the constant comparative method of data analysis was used. Conflicts between the management office and social welfare center of permanent rental housing could be classified into two aspects; personal and operational. Main reasons for the conflicts between two institutions were identified such as attitude of management office staffs, lack of cooperation, current administrative system, lack of management resources such as space and operation cost, and so on. Based on the results, some implications including institutional support and social complementary cooperation were suggested for improvement of management and welfare service system for the residents of permanent rental housing.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.63 no.5
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• pp.597-607
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• 2014

This paper proposes active power control and frequency support control schemes of wind turbine generation system by using modified Maximum Power Point Tracking(MPPT) of Permanent Magnet Synchronous Generator(PMSG). Most wind turbine generation system is completely decoupled from the power system and power output control with pitch control. According to the frequency deviation, however, MPPT control can not contribute to the frequency change of the power system due to its active power output control. For solving this, the de-loaded(DL) control scheme is constructed for the frequency support control, which is based on applying the active power output control in the rotor speed control of PMSG. The rotor speed by used in the proposed DL control scheme is increased more than the optimal rotor speed of MPPT, and then this speed improvement increases the saved kinetic energy(KE). In order to show the effectiveness of the proposed control scheme, the case studies have been performed using the PSCAD/EMTDC. The results show that the proposed active power output control scheme(DL control and KE discharge control) works properly and the frequency response ability of the power system can be also improved with the frequency support of wind farm.

• Proceeding of Spring/Autumn Annual Conference of KHA
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• 2006.11a
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• pp.509-514
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• 2006

This study aimed to suggest the implications to improve the management system of permanent public rental housing. For this purpose, qualitative data were collected by using the in-depth interview with 13 staffs of community welfare center and management office in permanent public rental housing complexes and 2 times of advisory committee meetings. To analyze the data gathered in this study, the constant comparative method of data analysis was used. Based on the results, some implications including institutional support and social complementary cooperation were suggested in terms of short and long term period.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.20 no.8
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• pp.717-726
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• 2010

For the application into a 1 kWh flywheel energy storage system(FESS), this paper presents the design scheme of radial and axial hybrid magnetic bearings which use bias fluxes generated by permanent magnets. In particular, the axial hybrid magnetic bearing is newly proposed in this paper, in which a permanent magnet is arranged in axial direction so that it can support the rotor weight as well as provide a bias flux for axial magnetic bearing. Such hybrid magnetic bearings consume very low power, compared with conventional electromagnetic bearings. In this paper, to stably support a 140 kg flywheel rotor without contact, design process is explained in detail, and magnetic circuit analysis and three-dimensional finite element analysis are carried out to determine the design parameters and predict the performance of the magnetic bearings.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1997.04a
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• pp.272-277
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• 1997

The axial bearing using two ring type permanent magnets to support the weight of a flywheel is proposed to reduce the bearing loss in a flywheel energy storage , system. Two permanent magnet makes stable force in axial direction but unstable force in lateral direction. The lateral unstable stiffness is identified quantitatively using flux analysis, and then through the rotor dynamic analysis on a rigid flywheel system the unstable effects on the system by the stiffness is investigated.

• Journal of Institute of Control, Robotics and Systems
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• v.11 no.7
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• pp.565-571
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• 2005

We present a novel speed estimation of a Permanent Magnet Synchronous Motor(PMSM) based on Support Vector Regression(SVR). The proposed method can estimate wide speed range, including 0.33Hz with full load, accurately in the steady and transient states where motor parameters variations are known without parameter estimator. Moreover, the method does not need offline training previously but is trained on-line. The training starts with the PMSM operation simultaneously and estimates the speed in real time. The experimental results shows the validity and the usefulness of the proposed algorithm for the 0.4Kw PMSM DSP(TMS320VC33) drive system.

• Journal of the Korea Concrete Institute
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• v.19 no.6
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• pp.701-706
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• 2007

This study evaluated the durability of high-performance shotcrete mixed in the proper proportions using alkali-free and cement mineral accelerators as a permanent support that maintains its strength for the long term. Durability tests were performed the chloride permeability, repeated freezing and thawing, accelerated carbonation, and the effects of salt environments. Test results showed that all the shotcrete mixes included silica fume had low permeability. In addition, after 300 freeze/thaw cycles, the shotcrete mix had excellent freeze/thaw resistance more than the 85% relative dynamic modulus of elasticity. The accelerated carbonation test results were no effect of accelerator type but, the depth of carbonation was greater in the shotcrete mix containing silica fume. No damage was seen in a salt environments. Therefore, the high performance shotcrete mix proportions used in this study showed excellent durability.