• Journal of international Conference on Electrical Machines and Systems
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• v.1 no.4
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• pp.505-508
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• 2012

A permanent magnet flux switching (PMFS) machine has a simple rotor, whilst both magnets and coils are set in the stator, resulting in easy removal of heat due to both copper loss and eddy current loss in magnets. However, the volume of magnets used in PMFS machines is usually larger than in conventional PM machines, and leakage flux does exist at the non-airgap side. To make full use of the magnets and gain higher power density, a novel 3-dimensional (3D) field PMFS machine is developed. It combines merits of the tubular linear machine, external-rotor rotary machine and axial-flux rotary machine, hence, offers high power density and peak torque capability, as well as efficient utility of magnets owing to the unique configuration of triple airgap fields.

• Geomechanics and Engineering
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• v.14 no.6
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• pp.509-517
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• 2018

This paper proposes a numerical methodology for capturing the complete curve of a pressuremeter test including initial or disturbed parts and loops through a stiffness-based approach adopted in three dimensional finite difference code, FLAC3D. In order to enable this, a new hyperbolic model was used to replace the conventional linear elastic model prior to peak strength of Mohr-Coulomb soil model and update or degradation of shear modulus was considered. Presented modeling approach and implemented constitutive model are impressively successful. It leads to obtain the whole set of parameters for characterizing sands and seems promising for modeling the most of geotechnical structures.

• ETRI Journal
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• v.37 no.1
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• pp.118-127
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• 2015

The power consumption of 3D many-core processors can be reduced, and the power delivery of such processors can be improved by introducing voltage island (VI) design using on-chip voltage regulators. With the dramatic growth in the number of cores that are integrated in a processor, however, it is infeasible to adopt per-core VI design. We propose a 3D many-core processor architecture that consists of multiple voltage clusters, where each has a set of cores that share an on-chip voltage regulator. Based on the architecture, the steady state temperature is analyzed so that the thermal characteristic of each voltage cluster is known. In the voltage scaling and task scheduling stages, the thermal characteristics and communication between cores is considered. The consideration of the thermal characteristics enables the proposed VI formation to reduce the total energy consumption, peak temperature, and temperature gradients in 3D many-core processors.

• Proceedings of the KIPE Conference
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• 2013.11a
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• pp.227-228
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• 2013

The paper is related to smart maximum power system based on program logic. Especially, this system compares the total demand power with the target power by using the signal from the digital kilo watt meter. Based on the power information by the maximum power control equipment the consumed future power is anticipated. In addition, through consumed future power the controllable target power is set, and it applies on the maximum power control equipment. User or manager would control the load efficiently through the simple programming which could control load based on the control sequence and relay. So this system could control load more efficient and stable. Also the conventional load control circuit is not needed. Therefore, it is possible to improve the simple system configuration, which is resulted in cost effective and time saving. So this system is anticipated on time and coast.

• 제어로봇시스템학회:학술대회논문집
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• 1991.10b
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• pp.1737-1741
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• 1991

The authors proposed a new two-dimensional(2D) positioning system by use of M-array and correlation technique which is suitable for noisy environment in '88KACC and its revised versions in '89KACC and '90KACC. This system uses the property of M-array that the autocorrelation function of the M-array has a sharp peak at its origin. In this paper, a new mark pattern is developed, instead of M-array, with which the two-dimensional positioning system becomes robust to rotation error of TV camera. The property of the rotation-free pattern is checked under various conditions, and it is shown that, by use of this rotation-free pattern, the positioning system can be used not only in a noisy environment but also in a roughly aligned set up of the TV camera.

• Proceedings of the Korea Concrete Institute Conference
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• 2001.05a
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• pp.789-794
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• 2001

The acoustic emission(AE) signal from concrete cylinder specimen during failure process under cycling compressive loads were recorded and analyzed. Different filters were set on the AE signal duration based on the characteristic of amplitude distribution. From the value of AE signal amplitude, which corresponds to the occurrence of the peak for AE hits, the AE signals from concrete compressive specimen were divided into five sections. The relationship between the AE signal section and the failure mechanism of these materials, analyzed on the meso-structure level was determined. Based on the experiments, the AE characteristics of each failure mechanism are given. The results show that the AE technique is a valuable tool to study the failure mechanism of concrete.

• Journal of the Korean Society for Precision Engineering
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• v.21 no.12
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• pp.44-51
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• 2004

In a micro-EDM, it is well known that an RC circuit is suitable as a discharge circuit because of its low pulse width and relatively high peak current. To increase machining speed without changing unit discharge energy, charge resistance should be decreased. But, when the resistance is very low, continuous (or normal) arc discharge occurs, electrode wear increases and machining speed is reduced remarkably. In this paper, an RC circuit with transistors is used in a micro-EDM. Experimental results show that the RC circuit with transistors can cut off a continuous (o. normal) arc discharge effectively if the duty factor and switching period of the transistor are set up optimally. Through experiments with varying charge resistances, it is shown that the RC circuit with transistors has about two times faster machining speed than that of an RC circuit.

• Journal of the Korean Society for Precision Engineering
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• v.1 no.2
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• pp.41-46
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• 1984

The machinability of calicium-deoxidized steel is studied in turning by being compared with that of Fe-Si deoxidized steel under a given set of cutting condition. Tool life, cutting force and cutting mechanism are examined on a few sorts of steel. It is found that adhesive layer "Belag" is developed on the cemented carbide tool and the peak value is observed at the cutting speed of 300m/min followed by gradual increase in the thickness of Belag with the increase of cutting speed. the maximum thickness of Belag is also shown at the feed of 0.3mm/rev. On the other hand, the tool life of carbide tool is more favorable than that of high speed steel (SKH 9) in cutting calcium- deoxidized steel. It is considered that the steel deoxidized with Ca-Si shows better machinability a little than that with Fe-Si. However, the cutting force and the shear angle of the former are similar to those of the latter in turning.n turning.

• Proceedings of the KIPE Conference
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• 2011.07a
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• pp.498-499
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• 2011

In this paper, the fundamental features of the arc stability DC arc furnace have been investigated, from the converter point of view. To compare of measurement arc data from DC arc furnace and the advanced arc simulations of magneto-hydrodynamics (MHD) and the well known Cassie-Mayr arc model have been extensively used. The MHD based arc simulation has been validated in the subcomponent level, for the free burning arc set up in the laboratory. The arc simulation predicted the arc voltage for different currents with the accuracy which satisfies engineering requirements. It has been shown that the arc current steepness at current zero determines the arc stability, and the associated peak arc resistance can be used as its quantitative measure. Based on the presented insight into the DC arc stability, a converter topology solution which realizes an optimal arc stability has been proposed. The main results presented in this paper provide a design guideline for the future DC arc furnace converter topology developments.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.58 no.6
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• pp.1087-1092
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• 2009

This paper presents a method for improvement of capacity payment in CBP(cost based pool) market. Capacity payments have been used as common mechanisms in various pools for compensating generators recognized to serve a for reliability purpose. Ideal pricing for capacity reserves by definition achieves a balance between economic efficiency and investment incentives. That is, prices must be kept close to costs, but not so low as to discourage investment. However, the price set is not easy. This paper concludes with market design recommendations that apply fuzzy theory for improvement of capacity payment. Following this model, market participants decided on their own based on their forecast to the market demand and the payment for it.