• Proceedings of the KSRS Conference
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• 2004.10a
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• pp.121-124
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• 2004

This paper proposed the method of creating image mosaic in automated fashion. It is well known that geometric and radiometric balance in adjacent images should be maintained in mosaicking process. The seam line to minimize geometric discontinuity was extracted using Minimum Absolute­Gray-Difference Sum considering constraint condition in search width. To maintain the radiometric balance of images acquired at different time, we utilized Match Cumulative Frequency, Match Mean and Standard Deviation and Hue Adjustment algorithm. The mosaicked image prepared by the proposed method was compared with those of commercial software. Experiments show that seam lines were extracted significantly well from roads, rivers. ridgelines etc. and Match Cumulative Frequency algorithm was performed pretty good in histogram matching

• Journal of the Korean Institute of Telematics and Electronics
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• v.10 no.4
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• pp.74-79
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• 1973

The Impcdance Matching Condition for maximum power out-pilt cf an Impact oscillator is calculated using the Van der pol's equation. From this calculation, it is found that the load impedance of the oscillator must be one half of the diode impedance for the maximum power output. To get an experimental proof for this result, tole impedance of the Impatt-diode was measured and accordingly the microwave oscillator designed and fabricated. The data obtaiped from the experiments agree fairly closely with the theoretical values.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.34S no.9
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• pp.109-117
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• 1997

A new relaxation algorithm based on distribution of matched errors and possibility is proposed to solve efficiently correspondence problem. This algorithm can be applied to various method, such as BMA, feature-, and region-based matching methods, by modifying its smoothness function. It consists of two stages which are transformation and iteration process. In transformation stage, the errors obtained by any matching algorithm are transformed to possibility values according to these statistical distribution. Each grade of possility is updated by some constraints which are defined as smoothness, uniqueness, and discontinuity factor in iteration stage. The discontinuity factor is used to reserve discontinuity of disparity. In conventional methods, it is difficult to find proper weights and stop condition, because only two factors, smoothness and uniqueness, have been used. However, in the proposed mthod, the more smoothing is not ocurred because of discontinuity factor. And it is efective to the various image, even if the image has a severe noise and repeating patterns. In addition, it is shown that the convergence rate and the quality of output are improved.

• Journal of Magnetics
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• v.18 no.2
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• pp.178-182
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• 2013

We have developed a new non-conventional electron paramagnetic resonance (EPR) spectrometer, in which no resonant cavity was used. We previously demonstrated a wide frequency range operation of an EPR spectrometer using two loop antennas, one for a microwave transmission and the other for signal detection [1]. In contrast to Ref. [1], the utilization of a microstrip antenna as a transmitter enhanced a capability of wide-band operation. The replacement of conventional capacitors with varactor diodes makes resonance condition easily reproducible without any mechanical action during tuning and matching procedure since the capacitance of the diodes is controlled electronically. The operation of the new EPR spectrometer was tested by measuring a signal of 1,1-diphenil-2-picrylhydrazyl (DPPH) sample in the frequency range of 0.8-2.5 GHz.

• The KSFM Journal of Fluid Machinery
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• v.18 no.6
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• pp.31-36
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• 2015

A multi-stage turbocharger system has been constructed for HALE UAV internal combustion engine. To boost rarefied intake air up to sea level condition, the turbocharger system should consist of 3 stages including heat exchanger located after compressor outlet to drop compressed air temperature. One dimensional system analysis has been conducted by matching required power between compressor and turbine and adequate turbochargers have been searched for from commercially available models targeting for automobiles. By applying commercial automobile turbochargers to the multi-stage turbocharger system, it is expected that considerable amount of research resources will be saved.

• Proceedings of the KIEE Conference
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• 2000.07c
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• pp.2213-2215
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• 2000

In this paper we implemented a novel re-entrant mode microstrip directional coupler for realizing the high directivity characteristic using finite element (FE) analysis. In microstrip configuration, the high directivity can be reached by matching the even- and odd-mode effective phase velocities. Through the values of capacitance obtained from 2-dimensional finite element(FE) analysis, the phase velocities for each mode and the design parameter were extracted for the proposed coupled-line configuration. Based on the extracted design parameter with phase matching condition we designed and fabricated 30dB directional coupler at 850MHz. Experimental results show good performance with excellent isolation.

• Journal of Institute of Control, Robotics and Systems
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• v.9 no.8
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• pp.640-646
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• 2003

We presents an edge-based point correlation algorithm for fast and stable visual inspection system. Conventional algorithms based on NGC(normalized gray-level correlation) have to overcome some difficulties in applying automated inspection systems to real factory environment. First of all, NGC algorithms involve highly complex computation and thus require high performance hardware for realtime process. In addition, lighting condition in realistic factory environments is not stable and therefore intensity variation from uncontrolled lights gives many troubles for applying NGC directly as pattern matching algorithm. We propose an algorithm to solve these problems, using thinned and binarized edge data, which are obtained from the original image. A point correlation algorithm with the thinned edges is introduced with image pyramid technique to reduce the computational complexity. Matching edges instead of using original gray-level image pixels overcomes problems in NGC method and pyramid of edges also provides fast and stable processing. All proposed methods are proved by the experiments using real images.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.41 no.5
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• pp.541-550
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• 1992

The fourth harmonic conversion(FHC) efficiency of high-power Nd laser pulse with wavelength of 1.054x10S0-6Tm using two KDP crystals(doubler adn quadrupler) was simulated numerically. Simulation results show that for the perfect phase-matching condition the FHC efficiency were 60-70% for several hundreds MW/cmS02T class and over 70% for GW/cmS02T class laser pulses. And the overall characteristics of FHC were discussed in terms of effects of input intensity, crystal length, and mismatch angle Δ$\theta$. Optimum method to FHC was type-II doubler & type-I quadrupler KDP crystal because type-II KDP doubler crystal has wide tolerance of acceptance matching-angle.

• Journal of Institute of Control, Robotics and Systems
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• v.9 no.11
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• pp.861-867
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• 2003

We propose a sliding surface design method for linear systems with mismatched uncertainties in the state space model. In terms of LMIs, we derive a necessary and sufficient condition for the existence of a linear sliding surface such that the reduced-order equivalent sliding mode dynamics restricted to the linear sliding surface is not only stable but completely invariant to mismatched uncertainties. We give an explicit formula of all such linear switching surfaces in terms of solution matrices to the LMI existence condition. We also give a switching feedback control law, together with a design algorithm. Additionally, we give some hints for designing linear switching surfaces guaranteeing pole clustering constraints or linear quadratic performance bound constraints. Finally, we give a design example in order to show the effectiveness of the proposed methodology.

• Proceedings of the IEEK Conference
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• 2005.11a
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• pp.363-366
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• 2005

In this paper, for detecting human faces under variations of lighting condition and facial expression, distance ranking feature and detection algorithm based on the feature are proposed. Distance ranking is the intensity ranking of a distance transformed image. Based on statistically consistent edge information, distance ranking is robust to lighting condition change. The proposed detection algorithm is a matching algorithm based on FFT and a solution of discretization problem in the sliding window methods. In experiments, face detection results in the situation of varying lighting condition, complex background, facial expression change and partial occlusion of face are shown