• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.13 no.10
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• pp.947-959
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• 2001

We propose a control scheme to control the indoor zone temperature via variable air volume (VAV) unit. To control the room temperature, state space model of the conditioned zone which is partitioned into nine artificial sectional regions is derived. The nonlinearity of the damper motion and actuator are considered for the practical use in the state space system description. The temperature control of the room temperature is performed by manipulating the degree of openness of the damper in relation to the local room temperature and the supplied air flow rate. In general, since a local temperature in the conditioned zone is measured, it is required to estimate the temperature values in each regions for the precise temperature control. We thus design a state observer to estimate the regional temperature, and use these values in the controller. The overall control system consists of the state observer based state feedback with the integral control. We compared the control results of the proposed scheme with those of cascade proportional and integral (PI) control, and showed that the scheme achieved precise control of the conditioned system.

• East Asian mathematical journal
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• v.38 no.5
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• pp.643-647
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• 2022

Let F² denote the space of entire functions f on ℂ that are square integrable with respect to the Gaussian measure $dG(z)={\frac{1}{\pi}}{e^{-{\mid}z{\mid}^2}}$, where dA(z) = dxdy is the ordinary area measure. The Fock-Dirichlet space $F^2_{\mathcal{D}}$ consists of all entire functions f with f' ∈ F². We estimate Taylor coefficients of functions in the Fock-Dirichlet space. The Fock-Nevanlinna space $F^2_{\mathcal{N}}$ consists of entire functions that possesses just a bit more integrability than square integrability. In this note we prove that $F^2_{\mathcal{D}}=F^2_{\mathcal{N}}$.

• Journal of the Korean Chemical Society
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• v.26 no.4
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• pp.195-204
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• 1982

Semi-empirical MO calculations, EHT, CNDO/2, MINDO/3, and MNDO met hods, were performed on various geometries of n-butane, n-alkyl radical and tetramethylene diracal (triplet) in order to compare eigenvalue and eigenvector properties with those obtained by STO-3G method. All methods predicted the same relative order of stabilities of various geometries for n-butane; geometrical preferences were found to be dominated by one-electron factor, ${\pi}$-orbital energy changes being more impotant in the semi-empirical methods. The hyperconjugative energy changes accompanying structural changes from $(n-{\sigma}{\ast})_{trans}$ to (n-{\sigma}{\ast})cis were underestimated in the EHT, CNDO/2 and MINDO/3, whereas those were overestimated in the MNDO. The net destabilizing effect of $(n-{\sigma}{\ast})_{trans}$ structure was mainly due to the large internuclear energy involved in the structure. Through-space interaction between $n_1$ and $n_2$ orbitals of diradical caused energy gap narrowing of ${\Delta}E_{sp}$ and ${\Delta}{\varepsilon}={\varepsilon}_0$-${\varepsilon}_{av}$; through-space interaction had opposing effect to that of through-bond interaction. Due to the less severe neglect of differential overlaps in the MNDO, this energy gap narrowing effect appeared amplified in the MNDO. In general orbital properties were found to be reproduced satisfactorily, but eigenvalue properties were not, in all the semi-empirical methods especially when ${\sigma}-{\sigma}{\ast}$ and n-$n-{\sigma}{\ast}$interactions were involved.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.36 no.3
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• pp.257-265
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• 2000

Brushless DC(BLDC) motors are widely used as AC servo motors in factory automation fields because of their quick instantaneous mobility, good energy saving efficiency and easiness of design for control system comparing with induction motors. Recently, a Two-Degree-of-Freedom(2DOF) PI control law has been adopted to some application parts to accomplish an advanced speed control of BLDC motors. The method can treat the two conflicting performances, minimum tracking errors versus reference inputs without large overshoot and rejection of some disturbances including modeling errors, independently. However, the method can not design the optimal system which is able to minimize tracking errors and energy consumption simultaneously. In this paper, a 2DOF integral type optimal servo control method is investigated to promote the speed control performances of BLDC motors considering energy consumption. In order to applicate the method to the speed servo system of the BLDC motor, the motor is modeled in the state space using the vector control and decoupling technique. To verify the validity of the suggested method, some simulations and experiments are performed.

• The Bulletin of The Korean Astronomical Society
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• v.45 no.1
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• pp.39.2-39.2
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• 2020

Based upon the previous heritage in the complete development of the infrared imaging spectrometer, NISS (Near-infrared Imaging Spectrometer for Star formation history) onboard NEXTSat-1, we are participating in the NASA MIDEX mission (PI Institute: Caltech), the all-sky infrared spectro-photometric surveyor SPHEREx (Spectro-Photometer for the History of the Universe, Epoch of Reionization, and Ices Explorer). The SPHEREx will provide us the first all-sky infrared spectro-photometric data set to probe the origin of our Universe, to explore the origin and evolution of galaxies, and to explore whether planets around other stars could harbor life. After the SPEHREx have passed the PDR (Preliminary Design Review) on this September, the fabrication of flight hardware will be started soon. As an international partner, KASI takes part in the hardware development, the operation and the science for the SPHEREx. Here, we report the status of the SPHEREx project and the progress in the Korean participation.

• Journal of Korea Society of Digital Industry and Information Management
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• v.5 no.1
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• pp.107-126
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• 2009

An Airport is important space and even stands for the country because diverse people from other countries use a variety of facilities in the gateway to the country. Therefore, It is urgent for those people to increase efficiency and convenience of its usage and also. It's worth accumulating those know-how and technologies. In this situation, Incheon International Airport aiming to be a hub of north-east Asia need to focus more on restructuring general process of passenger's travel based on PI perspectives then simply improving a process of passenger's travel and have been trying to realize the process based on Innovation perspectives with following precess innovation consisting 5 steps And to conclude, this study will help Incheon International Airport to be innovative in a system of passenger's travel service related to a utility of airport and then achieve a hub Airport of North-East Asia.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 2000.04a
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• pp.35-38
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• 2000

Conventional atom model must be criticized on the following four points.(1) natural motions between positive and negative entities are not circular motions but linear going and returning ones, for examples sexual motion, tidal motion, day and night etc.(2) Potential energy generation was neglected when electron changes its orbit from outer one to inner one. The hv is the kinetic energy of the photo-electron. The total energy difference between orbits comprises kinetic and potential energies. (3) The structure of the space must be taken into consideration because the properties of the electron do not changed during the transition from outer orbit to inner one even though it produces photon. (4) Total energy conservation law applies to the energy flow between mind and matter because we daily experiences a interconnection between mind and body.New atomic model 9the crystallizing $\pi$-bonding) was proposed in the journal of material processing technology since 1997 for the explanation of the mechanical behaviors in terms of physics. $\prod$-ray physics proved that the electrons can come out from in the nucleus and modern chemistry corresponds to the $\pi$-bonding by the nuclear electrons. The $\pi$-bonding structure of the protons outside the nucleus is that electrons move between protons of the different atoms. The perception step and the characteristic frequency in signal transduction is due to the accumulation of the $\pi$-rays outside of the proton before their absorption to the nucleus.

• Proceedings of the Korean Society for Cognitive Science Conference
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• 2000.05a
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• pp.71-75
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• 2000

Conventional atom model must be criticized on the following four points. (1) Natural motions between positive and negative entities are not circular motions but linear going and returning ones, for examples sexual motion, tidal motion, day and night etc. (2) Potential energy generation was neglected when electron changes its orbit from outer one to inner one. The hv is the Kinetic energy of the photo-electron. The total energy difference between orbits comprises kinetic and potential energies. (3) The structure of the space must be taken into consideration because the properties of the electron do not change during the transition form outer orbit to inner one even though it produces photon. (4) Total energy conservation law applies to the energy flow between mind and matter because we daily experiences a interconnection between mind and body. New atomic model (the crystallizing $\pi$-bonding) was proposed in the journal of material processing technology since 1997 for the explanation of the mechanical behaviors in terms of physics. $\prod$-ray physics proved that the electrons can come out from in the nucleus and modern chemistry corresponds to the $\pi$-bonding by the nuclear electrons. The $\pi$-bonding structure of the protons outside the nucleus is that electrons move between protons of the different atoms. The perception step and the characteristic frequency in signal transduction is due to the accumulation of the $\pi$-rays outside fo the proton before their absorption to the nucleus.

• Bulletin of the Korean Chemical Society
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• v.34 no.2
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• pp.374-378
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• 2013

Two novel binuclear metal-organic coordination complexes [$Cd_2(Hdpa)_4(bpy)_2$] (1), [$Dy_2(dpa)_2(bpy)_2(NO_3)_2-(H_2O)_2$](bpy) (2) (where $H_2dpa$ = biphenyl-2,2'-dicarboxylic acid, bpy = 2,2'-bipyridine) have been synthesized under hydrothermal conditions and characterized by single crystal X-ray diffraction, spectral method (IR), elemental analysis (EA), powder X-ray diffraction (XRD), electronic spectra (UV-vis), fluorescent in the solid state and thermogravimetric analysis (TGA). Complexes 1-2 crystallizes isomorphously in the Triclinic space group P-1. The ${\pi}-{\pi}$ stacking interactions and hydrogen-bonds play a vital role in determining the crystal packing and construction of the extended 3-D supramolecular network.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.66 no.1
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• pp.48-54
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• 2017

In this paper, hysteresis voltage control method is proposed to an unidirectional inverter control for piezoelectric load. Piezoelectric load has electrically RC characteristic, and is driven by the inverter to control the output voltage waveform. When controling the output waveform by PI control, appropriate gains need to be selected. However, hysteresis control may minimize the output distortion because it has maximum proportional gain. In addition, Hysteresis control algorithm has simple structure to realize and the response is fast. Although the switching frequency of the inverter by hysteresis control varies, the switching frequency for the piezoelectric load is lower than that by PI control for equivalent performance. In particular, on implementing the algorithm using FPGA, the algorithm can be implemented in fewer pabrics and the processing time can be reduced. The superiority of the proposed hysteresis voltage control was proved for piezoelectric load through simulation and experiment.