• The Bulletin of The Korean Astronomical Society
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• v.44 no.2
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• pp.57.4-57.4
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• 2019

BITSE is a project of balloon-borne experiments for a next-generation solar coronagraph developed by a collaboration with KASI and NASA. The coronagraph is built to observe the linearly polarized brightness of solar corona with a polarization camera, a filter wheel, and an aperture door. For the observation, the coronagraph is supported by the power distribution unit (PDU), a pointing system WASP (Wallops Arc-Second Pointer), telemetry & telecommand system SIP (Support Instrument Package) which are developed at NASA's Goddard Space Flight Center, Wallops Flight Facility, and Columbia Scientific Balloon Facility. The BITSE Command and Data Handling (C&DH) system used a cost-off-the-shelf electronics to process all data sent and received by the coronagraph, including the support system operation by RS232/422, USB3, Ethernet, and digital and analog signals. The flight software is developed using the core Flight System (cFS) which is a reusable software framework and set of reusable software applications which take advantage of a rich heritage of successful space mission of NASA. The flight software can process encoding and decoding data, control the subsystems, and provide observation autonomy. We developed a python-based testing framework to improve software reliability. The flight software development is one of the crucial contributions of KASI and an important milestone for the next project which is developing a solar coronagraph to be installed at International Space Station.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.12 no.1
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• pp.109-120
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• 2013

In this paper we proposed the design of the hybrid road lighting control system using solar-light generation. The proposed hybrid road lighting control system be power offer through hybrid controller using Solar-Light Generation, and it is designed so that it can control lighting up. To control supply of continuous power when during power shortages. And the gateway be transmit control command using zigbee to road lighting to ensure that automatic lighting control on human sensing. In this case, the gateway is apply the lighting control algorithm that decisions to the status of the system by a pre-set time schedule and be able to operate. In this paper, the proposed efficiency analysis results of a hybrid road lighting control system was consumed power of 129.6W per day, 3.8KW per month, 47.3KW per annual. As a result, it were able to increase the energy efficiency than existing lighting control system by reduce power consumption of 76.2% and the electricity prices of 76.8%.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38A no.12
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• pp.1079-1085
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• 2013

Due to the limited power supply resources, it is essential that the minimization of algorithmic operation and the reduction of the hardware logical-resources in the design of the satellite transponder. It is also required that the transponder process the signals of various bandwidth efficiently, that is suitble for the SDR-based implementation. This paper proposes a variable rate down sampler which can provide variable bandwidth and data rate for carrier, ranging and sub-band command signals respectively. The proposed down sampler can provide multiple $2^M$ decimated outputs from a single half band filter with recursive arithmetic architecture, which can minimize the hardware resources as well as the arithmetic operations. The algorithm for hardware implementation as well as the analysis for the passband flatness and aliasing is presented and varified by the FPGA implementation.

• Convergence Security Journal
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• v.17 no.5
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• pp.153-161
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• 2017

The gain a decision by a prediction supposition future combat. Take a future combat by the method fighting of U.S. Army in the Irak war. A make combat progress is from real time information to precision bombing for a guided weapon by GPS, a intelligence satellite, a pilotless scout plane, real time simultaneous and unification combat power are the kernel element of gain a decision fighting power by network in the ground, sky, marine, universe, cyberspace. The NCW is in a sense network center war organic be connected by networking a factor of operation. Any where networking information collection, command and decision, blow system. The Study on the improvement plan for Military combat power by base of NCW abainst the future War. Construct an integrate intelligence network apply to future combat.

• The Transactions of the Korean Institute of Power Electronics
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• v.18 no.6
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• pp.523-529
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• 2013

A sensorless speed control of a permanent magnet synchronous motor(PMSM) which utilizes MRAS based scheme to estimate rotor speed and position is presented. Considering an error between real and estimated rotor position values, a state equation of PMSM in the synchronous d-q reference frame is represented. A state equation of model system which uses estimated speed and nominal parameter values is expressed. To minimize the errors between the derivatives of d-q axis currents of real and model system, MRAS based adaptation mechanisms for the estimation of rotor speed and position are derived. On the other hand, for the acceleration stage of motor just before the sensorless operation, an acceleration scheme using only d-axis current control is proposed. To show the validity of the proposed scheme, experimental works are carried out and evaluated. During acceleration stage, the acceleration scheme using only d-axis current command shows good acceleration performance and controlled current level. For the sensorless operation, at low speed (5% of rated speed), a good performance is observed.

• Journal of Korean Institute of Industrial Engineers
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• v.30 no.1
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• pp.65-75
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• 2004

The enhancement of C2(Command and Control) system will increase effectiveness of individual force power in combat engagement. Especially, available time of a given engaging force and information accuracy are the most influencing factors to increment of combat effectiveness after enhancement of C2 system. In this paper, by using Schutzer's C2 Theory and Measures of Effectiveness, we developed several analytical functions representing the relationships between C2 system enhancement and two most critical variables, available time and information accuracy. As a result of functional analysis, we showed C2 system enhancement and combat effectiveness have positive and non-linear relationship. The higher level of C2 system be required, the better combat effectiveness of force power can be obtained. Additionally, we proposed a proposition that the combat effectiveness of C2 system is more sensitive to available time than to information accuracy, which might be very important issue for further research in this field.

• The Transactions of the Korean Institute of Power Electronics
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• v.17 no.6
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• pp.478-485
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• 2012

In this paper, a new PWM method is proposed to reduce the input current harmonics of 3 phase PWM rectifier. In the conventional carrier comparison PWM method, a triangular wave is generally used as the carrier wave. However, the large d-axis current ripple by the triangle carrier wave may be a source of large input current THD(Total Harmonic Distortion). In this paper, a new carrier comparison PWM method with saw tooth wave is proposed. Depending on the sector where the voltage command vector places, one of the rising or falling saw tooth wave is selected. To reduce the switching losses of the saw tooth carrier PWM, the discontinuous PWM is also presented. The proposed PWM method can reduce the d-axis current ripple as well as the switching losses. The performance of the conventional and proposed PWM methods is verified by the simulation and experimental results.

• Journal of Power Electronics
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• v.13 no.4
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• pp.656-668
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• 2013

This paper presents a wavelet-fuzzy based controller for indirect field oriented control of three-phase induction motor drives. The discrete wavelet transform is used to decompose the error between the actual speed and the command speed of the induction motor drive into different frequency components. The transformed error coefficients along with the scaling gains are used for generating the control component of the motor. Self-tuning fuzzy logic is used for online tuning of the scaling gains of the controller. The proposed controller has the ability to meet the speed tracking requirements in the closed loop system. The complete indirect field oriented control scheme incorporating the proposed wavelet-fuzzy based controller is investigated theoretically and simulated under various dynamic operating conditions. The simulation results are compared with a conventional proportional integral controller and a fuzzy based controller. The speed control scheme incorporating the proposed controller is implemented in real time using a digital processor control board. Simulation and experimental results validate the effectiveness of the proposed controller.

• Journal of Wind Energy
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• v.2 no.1
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• pp.90-96
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• 2011

The purpose of this paper is to describe the control system for optimal performance of 2MW gearless PMSG wind turbine system, and to afford some techniques of the algorithm selection and design optimization of the wind turbine control system through analysis of load calculation and control characteristic. Wind turbine control system is composed of the main control system and remote control and monitoring system. The main control system is industrial PC based controller, and the remote control and monitoring system is a server based computer system. The main control system has a supervisory control of the wind turbine with operation procedures and power-speed control through the torque control by pitch angle. There are some applications to optimize the wind turbine system at the starting mode with increasing of rotor speed, and cut-in operating mode to prevent trundling cut-in and cut-out, a gain scheduling of pitch PID controller, torque scheduling and limitation of generation power by temperature limitation or remote command by remote control and monitoring system. Also, the server operation program of the remote control and monitoring system and the design of graphical display are described in this paper.

• Journal of architectural history
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• v.29 no.5
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• pp.29-40
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• 2020

Ui-Gum-Bu(義禁府) is regarded as a key organization that reflects the power of the royal authority, mainly because it directly obeys the king's command and retains the power to punish or pardon government officials for severe crimes such as treason or significant breach of Confucian ethics. For this reason, Ui-Gum-Bu held a higher place in the organizational hierarchy of the government than other similar offices such as Hyung-Jo(刑曹), Sa-Heon-Bu(司憲府) and P o-Do-Cheong(捕盜廳). This characteristic of Ui-Gum-Bu is also evident in the architectural style and composition of the office building. The figures of the Ui-Gum-Bu office is depicted in detail in the paintings listed in 『Gum-Oh-Gye-Cheop(金吾契帖』, a record of Ui-Gum-Bu office meetings, and descriptions in the code book 『Gum-Oh-Hun-Rog(金吾契帖)』, both written in 18th century. The purpose of this study is to reveal the overall transition process of the Ui-Gum-Bu office building from the beginning until its demolition in the early 20th century. Based on research materials of 18th century, its architectural composition and characteristics will be dealt in detail.