• 자원환경지질
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• 제27권6호
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• pp.563-569
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• 1994

Resistivity Image Profiling has been applied to a geological survey in the Keoje-do area. Survey lines are located near the KD-02 and KD-06 wells in the area, where we have already sampled all rock cores and carried out several kinds of geophysical logs. In each site a resistivity cross-section is obtained by inverting pole-pole apparent resistivities. Comparing the reconstructed resistivity section with the rock cores and logging data obtained in the well provides a detailed picture of subsurface geology. The geology of KD-02 site is composed of conglomerate, sandstone and shale with fractures. The reconstructed resistivity image is useful for assessing the grade of weathering of these rocks. The KD-06 site is mainly underlain by granitic rocks, and its fresh basement can be delineated by resistivities over $1000{\Omega}{\cdot}m$.

• 한국소음진동공학회논문집
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• 제11권6호
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• pp.223-232
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• 2001

Aiming at a small axial pump with a levitated rotor, an axial-type self-bearing motor is presented, which has a rotor wish four permanent magnets and two stators with two-pole three-phase windings. In this system, only the axial motion of rotor is actively controlled by two opposite self-bearing motors just like in the case of an axial magnetic bearing, while the other motions are passively stable. For rotation, It follows the theory of a four-pole three-phase synchronous motor. This paper Introduces schemes for design and control of the self-bearing motor and shows some experimental results to Prove the feasibility of application for the axial Pump.

• 대한수학회지
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• 제35권1호
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• pp.127-134
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• 1998

It is proved [6] that there exists a basis of $L^\Gamma$ (the space of meromorphic vector fields on a Riemann surface, holomorphic away from two fixed points) represented by the vector fields which have the expected zero or pole order at the two points. In this paper, we carry out the same task for the quadratic differentials. More precisely, we compute a basis of $Q^\Gamma$ (the sapce of meromorphic quadratic differentials on a Riemann surface, holomorphic away from two fixed points). This basis consists of the quadratic differentials which have the expected zero or pole order at the two points. Furthermore, we show that $Q^\Gamma$ has a Lie algebra structure which is induced from the Krichever-Novikov algebra $L^\Gamma$.

• 한국정밀공학회지
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• 제12권6호
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• pp.96-104
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• 1995

A study for a lathe to machine workpiece with noncircular cross-section is presented. The noncircular cutting is accomplished by controlling radial tool position synchronized with revolution angle of the spindle according to the desired cross-sectional shape. A learning control algorithm is suggested for the tool positioning. The learning law of the algorithm is based on pole-zero cancellation, which guarantees the control stability. The control performances are analyzed and simulated on a numerical computer that the effectiveness of the control algorithm is convinced. The algorithm is tested on a conventional NC-lathe which shows some successful results.

• 천문학회보
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• 제45권1호
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• pp.35.2-35.2
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• 2020

Submillimeter galaxies (SMGs) have played an important role in the understanding of galaxy evolution and cosmic star formation history at high redshift because they are known as being located at z ~ 2 and harbor a vigorous star formation. Therefore studying properties of SMGs can lead us to understand evolution of massive and actively star forming galaxies and distribution of cosmic star formation density. Recently we detected 548 SMGs near North Ecliptic Pole with JCMT/SCUBA-2 from the JCMT large program covering about 2 deg2 so far. To derive their physical parameters, we compiled a multi-wavelength photometry ranging from optical (0.3 ㎛) to submillimeter (850 ㎛) by cross-identifying counterparts at different wavelengths. In order to find counterparts, we used either VLA-1.4 GHz image and/or Spitzer/IRAC 3.6 ㎛, 4.5 ㎛ image. The number of SMGs with relatively robust counterparts is 349. In this talk, we present photometric redshifts, stellar mass, star formation rates, total infrared luminosity, and AGN fraction of these 349 SMGs derived through SED fitting analysis.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1996년도 Proceedings of the Korea Automatic Control Conference, 11th (KACC); Pohang, Korea; 24-26 Oct. 1996
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• pp.324-327
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• 1996

This paper describes the robust controller design methods applied to the problem of an automatic system for tow-vehicle/trailer combinations. This study followed an inverse Linear Quadratic Regulator(LQR) approach which combines pole assignment methods with conventional LOR methods. It overcomes two concerns associated with these separate methods. It overcomes the robustness problems associated with pole placement methods and trial and error required in the application of the LQR problem. Moreover, a Kalman filter is used as the observer, but is modified by using the loop transfer recovery (LTR) technique with modified transmission zero assignment. The proposed inverse LQG,/LTR controllers enhances the forward motion stability and maneuverability of the combination vehicles. At high speeds, where the inherent yaw damping of the vehicle system decreases, the controller operates to maintain an adequate level of yaw damping. At backward moton, both 4WS (2WS tow-vehicle, 2WS trailer) and 6WS (4WS tow-vehicle, 2WS trailer) control laws are proposed by using inverse LQG/LTR method. To evaluate the stability and robustness of the proposed controllers, simulations for both forward and backward motion were conducted using a detailed nonlinear model. The proposed controllers are significantly more robust than the previous controllers and continues to operate effectively in spite of parameter perturbations that would cause previous controllers to enters limit cycles or to loose stability.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1992년도 하계학술대회 논문집 B
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• pp.626-628
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• 1992

GCB(Gas Circuit Breaker) and GIS(Gas Insulated Switchgear) using $SF_6$ are worldwidely applied over 72.5KV classes. It Is known that $SF_6$ gas has the most superior characteristics among the extingushing and insulating media. Our Company has produced GCB and GIS from early 1980's and at present, we are producing 362KV 40KA class which is the highest voltage in our country. According to change KEPCO's standards (ESB standards), our company has redeveloped and tested for all productions type from 1989. During redeveloping, we largely contribute raise reliability of power system, through all the more improvement for performance and quality of manufactures. One of them, we developed 170KV 50KA GCB with common three-pole operating mechanism and sucessfully completed test of KERI under KEPCO presence, at first in our country. Thus, we announce the outline of it.

• 전기학회논문지
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• 제64권6호
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• pp.954-959
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• 2015

In this paper, 110kW high output density, high efficiency Permanent Magnet Synchronous Motor which can be applied on tram’s traction system is introduced, along with its output and loss characteristics. The motor model is 2pole 18slot model and its size has been reduced through the high speed for high output density. Especially, structure and retainer sleeve structure is applied to its structure, which is also appropriate for high speed rotation. This kind of structure has eddy current loss problem on the surface of rotor, which must be reduced for high output density design. This study has designed the most optimized additional design parameter in order to improve the output characteristics and efficiency of previous produced 2pole 18 slot 110kW motor model and how the width of airgap affects from the loss perspective is mainly analyzed. Finally, the analysis on the extent of the efficiency improvement effect compared to the previous model has performed through electromagnetic FEM analysis. The influence of airgap flux density distribution has also been thoroughly examined.

• 센서학회지
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• 제14권6호
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• pp.409-414
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• 2005

For an intelligent vehicle driving which uses magnetic markers and magnetic sensors, we can get every kind of road information while moving the vehicle if we use the code that is encoded with N, S pole direction of markers. If we make it an only aim to move the vehicle, it becomes easy to control the vehicle the more we put markers close. By the way, to recognize the direction of a marker pole it is much better that the markers have no effect each other. To get road informations and move the vehicle autonomously we propose the methods of arranging magnetic sensors and algorithm of recognizing the position of the vehicle with those sensors. We verified the effectiveness of the methods with computer simulation.

• 한국생산제조학회지
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• 제24권6호
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• pp.613-618
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• 2015

In recent years, WorldSID has been continuously developed and investigated to be the representative biofidelic anthropomorphic test device (ATD) as well as the device for replacement of the current EuroSID-2. In Korea, the side impact accident is one of the major severe accidents in terms of the number of accidents and fatality. Since 2003, the side crash test with a speed of 50 kph in the perpendicular direction has been initiated as a safety standard with EuroSID-1 at the first stage. Simultaneously, a 55 kph impact test has been conducted as a part of Korean New Car Assessment (KNCAP). Currently, only EuroSIDE-2 is accepted as a regulatory tool for vehicle certification and KNCAP. The tests with WorldSID are conducted experimentally in order to use WorldSID of the KNCAP in near future.