• Proceedings of the Korea Society for Energy Engineering kosee Conference
• /
• 1996.10b
• /
• pp.34-44
• /
• 1996

N-machine produces more than input energy at above 3000 rpm. any space energy is absorbed when the N-machine is rotating at a very high velocity. Laws of electromagnetics verify that normal conduction is due to that electrons moves from one three-dimensional crystallizing ${\pi}-bonding$ orbital to next. The ${\pi}-far$ infrared rays are generated from the resonance and rotation of the electrons on the orbitals of three-dimensional crystallizing ${\pi}-bonding$ atoms. Material in universe is composed of ${\pi}-rays$, which have alternative outward electric field. If the alternative outward electric fields of the ${\pi}-rays$ are resonant each other they make attraction force, which is the gravity. The collection of space energy is due to a attraction force between the radially alternating electric field and the ${\pi}-far$ infrared rays in the space. Electrons flow by absorbed density difference of ${\pi}-far$ infrared rays along a conduction wire, which also verifies that normal electron conduction is due to a flow from one three-dimensional crystallizing ${\pi}-bonding$ orbital to next.

• Proceedings of the KIEE Conference
• /
• 2011.07a
• /
• pp.1023-1024
• /
• 2011

This paper deals with an improved core loss calculation of Linear Oscillatory Motor from curve fitting method using modified Steinmetz equation considered anomalous loss. For an accurate calculation, magnetic field analyses in stator core considering, magnetic field analyses in stator core considering the time harmonics are performed. And using the nonlinear finite element analysis (FEM), we applied separated rotating and alternating magnetic filed to core loss calculation.

• KIEE International Transactions on Electrophysics and Applications
• /
• v.3C no.6
• /
• pp.211-215
• /
• 2003

Alternating current (AC) losses of two Bi-2223 ([Bi, Pb] : Sr : Ca : Cu :O = 2:2:2:3) tapes [one untwisted (Tape I, twist-pitch of $\infty$ mm) and the other with a twist-pitch of 8mm (Tape II) ] were measured and compared. These samples, produced by the powder-in-tube (PIT) method, are multi-filamentary and have a Ag/Au and Ag matrix, respectively. Susceptibility measurements were conducted while cooling in a magnetic field. Flux loss measurements were conducted as a function of ramping rate, frequency and field direction. The AC flux loss increases as the twist-pitch of the tapes decreased, in agreement with the Norris Equation.

• Proceedings of the KIEE Conference
• /
• 2009.04b
• /
• pp.55-57
• /
• 2009

This paper deals with an improved core loss calculation under the load conditions, namely, no-load, AC-load and DC-load of multi-pole PM generator from curve fitting method using modified Steinmetz equation considered anomalous loss. For an accurate calculation, magnetic field analyses in stator core considering the time harmonics are performed. And using the nonlinear finite element analysis (FEA), we applied separated rotating and alternating magnetic field to core loss calculation. In order to verify the core loss results by proposed method, the experimental system for no-load core loss measurement has been implemented with DC motor, power analyzer and manufactured PM generator. And, the analysis results with rotational speed agree extremely well with those obtained by measurement.

• Journal of the Korean Society of Combustion
• /
• v.16 no.2
• /
• pp.33-39
• /
• 2011

We demonstrated heat generation efficiency of the magnetic hyperthermia system to find optimal condition using gelatin tissue phantom. Magnetic hyperthermia induction can be used to make heat generation with different concentration of $Fe_3O_4$ iron oxide inside tissue phantom and magnetically labeled cells by applying AC magntic field at a frequency of 145 kHz. It was observed that the maximum temperature achieved in the magnetic gelatin tissue phantom increased with the concentration of $Fe_3O_4$ iron oxide and alternating magnetic field intensity. Results were discussed with respect to further optimization of therapeutic technique for biomedical application with modified functional nanoparticles.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.24 no.1
• /
• pp.114-123
• /
• 2000

The flow structure around a rotating axial-fan was experimentally investigated using a phase averaging velocity field measurement technique. The fan blades were divided into 4 different phases, for which 500 velocity fields were acquired for each phase angle with a 2-frame PTV system. Velocity field measurements were also carried out at two planes parallel to the axis of rotation, with offsets toward the radial direction of the fan. For accurate synchronization of the PTV system with the phase of the axial fan, two synchronization circuits were employed with a photo-detector attached to the rotating shaft. The phase averaged velocity fields show periodic variations with respect to the blade phase. The periodic formation of vortices at the blade tip is also observed in vorticity contour plots. Locations of local maximum turbulence intensities in the axial and radial directions are found to be located in an alternating pattern. These experimental results can be used to validate numerical calculations and to understand the flow characteristics of an axial fan.

• Progress in Superconductivity
• /
• v.5 no.2
• /
• pp.89-93
• /
• 2004

We have studied alternating transport current losses in the vertically stacked high temperature superconducting tapes(HTS) using numerical techniques. In the case of stacked conductors, HTS tapes are exposed to self-field generated by transport current itself and also experienced external magnetic field around adjacent tapes. It is well known that magnetic interactions between neighbored tapes have significant effect on their properties of superconducting tapes such as current distribution, AC loss, and critical current. In this paper, we investigated the transport current losses in stacked conductors consisting of a few of the HTS tapes using numerical analysis. Current distributions are calculated in HTS tape cross-section taking account of magnetic field dependencies, which are represented superconducting nonlinear properties. Dissipated losses in tape and stacked conductors were integrated with current distribution and electric field intensity in the whole conductor region. Finally estimated results were discussed and verified through the analytical theory.

• Journal of the Korean Crystal Growth and Crystal Technology
• /
• v.19 no.5
• /
• pp.215-222
• /
• 2009

Many concepts of external magnetic field applications in crystal growth processes have been developed to control melt convection, impurity content and growing interface shape. Especially, travelling magnetic fields (TMF) are of certain advantages. However, strong shielding effects appear when the TMF coils are placed outside the growth vessel. To achieve a solution of industrial relevance within the framework of the $KRISTMAG^{(R)}$ project inner heater-magnet modules(HMM) for simultaneous generation of temperature and magnetic field have been developed. At the same time, as the temperature is controlled as usual, e.g. by DC, the characteristics of the magnetic field can be adjusted via frequency, phase shift of the alternating current (AC) and by changing the amplitude via the AC/DC ratio. Global modelling and dummy measurements were used to optimize and validate the HMM configuration and process parameters. GaAs and Ge single crystals with improved parameters were grown in HMM-equipped industrial liquid encapsulated Czochralski (LEC) puller and commercial vertical gradient freeze (VGF) furnace, respectively. The vapour pressure controlled Czochralski (VCz) variant without boric oxide encapsulation was used to study the movement of floating particles by the TMF-driven vortices.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.25 no.5
• /
• pp.741-749
• /
• 2001

An inhomogeneous hyperbolic electric field is established among two-dimensional quadrupole electrodes to which an ac voltage is applied. Conditions under which charged particles are focused into a narrow axis region of the plug laminar flow are discussed. The aerodynamic forces influence the behavior of the charged particles in the quadrupole electric field. We derived the dimensionless equations of motion of a charged particle in the alternating quadrupole electric field, and discussed particle trajectories and focusing performance in terms of two dimensionless parameters, which are functions of particle size, operating pressure, and the amplitude and frequency of applied AC voltage, with the results of numerical simulations and experiments.

• Journal of the Korea Computer Graphics Society
• /
• v.22 no.3
• /
• pp.21-29
• /
• 2016

Cell segmentation is an important but time-consuming and laborious task in biological image analysis. An automated, robust, and fast method is required to overcome such burdensome processes. These needs are, however, challenging due to various cell shapes, intensity, and incomplete boundaries. A precise cell segmentation will allow to making a pathological diagnosis of tissue samples. A vast body of literature exists on cell segmentation in microscopy images [1]. The majority of existing work is based on input images and predefined feature models only - for example, using a deformable model to extract edge boundaries in the image. Only a handful of recent methods employ data-driven approaches, such as supervised learning. In this paper, we propose a novel data-driven cell segmentation algorithm for bright-field microscopy images. The proposed method minimizes an energy formula defined by two dictionaries - one is for input images and the other is for their manual segmentation results - and a common sparse code, which aims to find the pixel-level classification by deploying the learned dictionaries on new images. In contrast to deformable models, we do not need to know a prior knowledge of objects. We also employed convolutional sparse coding and Alternating Direction of Multiplier Method (ADMM) for fast dictionary learning and energy minimization. Unlike an existing method [1], our method trains both dictionaries concurrently, and is implemented using the GPU device for faster performance.