• Proceedings of the IEEK Conference
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• 2003.07e
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• pp.2323-2326
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• 2003

Theoretical analysis of the depth measurement system with the use of a single camera and a rotating mirror has hem done. A camera in front of a rotating mirror acquires a sequence of reflected images, from which depth information is extracted. For an object pint at a longer distance, the corresponding pixel in the sequence of images moves at a higher speed. In this paper, the principle d the depth measurement-based on the relation of the pixel movement speed and the depth of objects have been investigated. Also, necessary mathematics to implement the technique is derived and presented. The factors affecting the measurement precision have been studied Analysis shows that the measurement m increases with the increase of depth. The rotational angle of the mirror between two image-takings also affects the measurement precision. Experimental results using the real camera-mirror setup are reported.

• Proceedings of the KIEE Conference
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• 1995.11a
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• pp.444-446
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• 1995

This paper deals with semisphere-type sensor fo measuring the electric field waveforms by lightning discharges. The theoretical principle and design rule of the device are introduced, and also the calibration and application investigations are carried out. From the calibration experiments, the frequency bandwidth of the semisphere-type electric field measuring device ranges from 200 [Hz] to 1.56 [MHz], and the sensitivity of sensor is 0.96 [mV/V/m]. The electric field waveforms produced by lightning discharges were observed for June and August 1995. It is shown that the electric field waveforms produced at the distance of more than 50 [km] include only radiation component.

• Journal of the Korea Computer Industry Society
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• v.9 no.3
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• pp.105-114
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• 2008

We present an eye tracking system using a low cost 3D CMOS imager for 3D displays that ensures a correct auto stereoscopic view of position- dependent stereoscopic 3D images. The tracker is capable of segmenting the foreground objects (viewer) from background objects using their relative distance from the camera. The tracker is a novel 3D CMOS Image Sensor based on Time of Flight (TOF) principle using innovating photon gating techniques. The basic feature incorporates real time depth imaging by capturing the shape of a light-pulse front as it is reflected from a three dimensional object. The basic architecture and main building blocks of a real time depth CMOS pixel are described. For this application, we use a stereoscopic type of display using parallax barrier elements that is described as well.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2002.05a
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• pp.44-47
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• 2002

In order to make a doubly curved sheet metal effectively, a sheet metal forming process has been developed by adopting the flexibility of the incremental forming process and the principle of bending deformation which causes slight deformation to thickness. The developed process is an unconstrained forcing process with no holder. For this study, the experimental equipment is set up with the roll set which consists of two pairs of support rolls and one center roll. In the experiments using aluminum sheets and FEM simulation, it is found that the curvature of the formed sheet metal is determined by controlling the distance between supporting rolls in pairs and the forming depth of the center roll. The FEM simulation of the forming process using the roll set along the one path shows the distributions of the curvatures in two directions along the path, and gives information about the characteristics of the proposed forming process.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2012.10a
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• pp.636-642
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• 2012

Delay-and-sum (DAS) Planar Beamforming has been a widely used Noise Source Identification Technique for the last decade. It is a quick one shot measurement technique being able to map sources that are larger than the array itself. The spatial resolution is proportional to distance between array and source, and inversely proportional to wavelength, thus the resolution is only good at medium to high frequencies. Improved algorithms using iterative de-convolution techniques offers up to ten times better resolution. The principle behind these techniques is described in this paper, as well as measurement examples from the automotive industry are presented.

• Proceedings of the KIEE Conference
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• 1987.11a
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• pp.267-271
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• 1987

The test cell for preventing the edge effect reducing the intrinsic breakdown strength of polypropylene film and measuring the intrinsic breakdown strength of the film was developed. The new approach was to develope an electrode system with an edge region which is carefully graded over an extended distance. The new test arrangement employed a central circular electrode at high voltage and a set of nine concentric surrounding rings each controlled in potential by external grading resistors to be at decreasing potentials from that at the center in 10% increments. Two different size structures using the same basic principle were tried and were both found to be successful. The test electrodes were manufactured using standard printed circuit technology and were chosen to be copper on high dielectric constant GIO board.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.30 no.10 s.253
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• pp.1293-1297
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• 2006

In this paper, kinematic analysis of a double-action link-type die set for enclosed die forging is carried out. The structure of the die set and its operational principle during enclosed die forging are introduced in detail. A closed-form solution of the relative velocity of the middle plate with respect to the upper plate after the upper and lower dies are enclosed is given in terms of the link lengths and the distance from the lower pin to the upper pin of the link system. The effect of the link lengths on both strokes and velocities is investigated. It has been shown that the relative velocity of the middle plate with respect to the upper plate varies almost linearly with the stroke of the upper plate.

• Proceedings of the KIEE Conference
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• 1994.07b
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• pp.1419-1421
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• 1994

The method of suppression based on the principle of energy trapping effect is very effective at high frequency. In this paper, We intended to get resonant frequency and bandpass filer characteristics in appling to vibration mode of PZT-4 and PZT-8 using trapped energy phenomenon. First, we theoretically analyzed a piezoelectric ceramic filter characteristics changing the thickness of ceramic plate, electrode spacing and distance between the two pairs of electrodes. We also experimentally investigated characteristics of ceramic filter made.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.11 no.3
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• pp.292-300
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• 1999

Fin conduction not only enhances heat transfer to the ambient air but also increases tube-to-tube conduction. The latter is known to deteriorate the heat exchanger performance. Heat conduction between neighboring tubes thorough the fin is numerically investigated for accurate performance analysis of plate finned-tube heat exchangers. Governing equations for arbitrary plate fin are solved and the temperature distribution is obtained using the principle of superposition. Analysis is made using finite element method by changing the shapes of fin, the arrangements of tubes and the fin parameter mD. It is found that tube-to-tube conduction is significant when mD is small or the distance between neighboring tubes is small.

• Journal of Integrative Natural Science
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• v.5 no.2
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• pp.120-126
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• 2012

This paper describes the algorithm that lowers the dimension, maintains the gesture recognition and significantly reduces the eigenspace configuration time by combining the higher correlation feature information and Principle Component Analysis. Since the suggested method doesn't require a lot of computation than the method using existing geometric information or stereo image, the fact that it is very suitable for building the real-time system has been proved through the experiment. In addition, since the existing point to point method which is a simple distance calculation has many errors, in this paper to improve recognition rate the recognition error could be reduced by using several successive input images as a unit of recognition with K-Nearest Neighbor which is the improved Class to Class method.