• The KIPS Transactions:PartB
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• v.11B no.1
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• pp.27-34
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• 2004

This paper proposes a method to trace and interpret a moving object based on the information which can be directly obtained from MPEG-2 compressed video stream without decoding process. In the proposed method, the motion flow is constructed from the motion vectors included in compressed video. We calculate the amount of pan, tilt, and zoom associated with camera operations using generalized Hough transform. The local object motion can be extracted from the motion flow after the compensation with the parameters related to the global camera motion. Initially, a moving object to be traced is designated by user via bounding box. After then automatic tracking Is performed based on the accumulated motion flows according to the area contributions. Also, in order to reduce the cumulative tracking error, the object area is reshaped in the first I-frame of a GOP by matching the DCT coefficients. The proposed method can improve the computation speed because the information can be directly obtained from the MPEG-2 compressed video, but the object boundary is limited by macro-blocks rather than pixels. Also, the proposed method is proper for approximate object tracking rather than accurate tracing of an object because of limited information available in the compressed video data.

• Journal of Korea Multimedia Society
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• v.13 no.3
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• pp.438-456
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• 2010

Iris recognition uses a unique iris pattern of user to identify person. In order to enhance the performance of iris recognition, it is reported that the diameter of iris region should be greater than 200 pixels in the captured iris image. So, the previous iris system used zoom lens camera, which can increase the size and cost of system. To overcome these problems, we propose a new method of enhancing the accuracy of iris recognition on low-resolution iris images which are captured without a zoom lens. This research is novel in the following two ways compared to previous works. First, this research is the first one to analyze the performance degradation of iris recognition according to the decrease of the image resolution by excluding other factors such as image blurring and the occlusion of eyelid and eyelash. Second, in order to restore a high-resolution iris image from single low-resolution one, we propose a new method based on multiple multi-layered perceptrons (MLPs) which are trained according to the edge direction of iris patterns. From that, the accuracy of iris recognition with the restored images was much enhanced. Experimental results showed that when the iris images down-sampled by 6% compared to the original image were restored into the high resolution ones by using the proposed method, the EER of iris recognition was reduced as much as 0.133% (1.485% - 1.352%) in comparison with that by using bi-linear interpolation

• Journal of Electrical Engineering and Technology
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• v.4 no.2
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• pp.168-174
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• 2009

An application of wavelet analysis to power system transient generated signals is presented in this paper. With the time-frequency localisation characteristics embedded in wavelets, the time and frequency information of a waveform can be presented as a visualised scheme. This feature is very important for non-stationary signals analysis such as the ones generated from power system disturbances. Unlike the Fourier transform, the wavelet transform approach is more efficient in monitoring fault signals as time varies. For time intervals where the function changes rapidly, this method can zoom in on the area of interest for better visualisation of signal characteristics.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.28 no.6
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• pp.867-875
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• 2004

In order to inspect burr geometry and hole quality in micro-drilling processes, a cost-effective method using an image processing and shape from focus (SFF) methods on the machine tool is proposed. A CCD camera with a zoom lens and a novel illumination unit is used in this paper. Since the on-machine vision unit is incorporated with the CNC function of the machine tool, direct measurement and condition monitoring of micro-drilling processes are conducted between drilling processes on the machine tool. Stainless steel and hardened tool steel are used as specimens, as well as twist drills made of carbide are used in experiments. Validity of the developed system is confirmed through experiments.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.167.6-167
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• 2001

The cylindrical environment maps of image-based representation methods make high-quality, simple and low-price real-time navigation possible. In this paper, we propose a method to navigate from one viewpoint to the next in the virtual inside space, composed of several cylindrical environment maps. Our system is classified into the two modules. first of all, the panoramic image viewer that employs the rotation and zoom-in/out methods to navigate the virtual inside space, such as the Quicklime VR. The other is smooth real-time navigation using cubic mesh interpolation when the viewpoint moves from one environment map to another in the virtual space.

• Journal of Engineering Education Research
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• v.24 no.6
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• pp.50-59
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• 2021

This paper is a study on the case of online classes in engineering·humanities convergence subjects, and the purpose of this study is to explore the possibility of effective online convergence classes by describing in detail how to design and operate online classes, and analyzing the effects and limitations of online classes. Such study will serve as a model for online classes needed in the new normal era, which is facing a turning point in education.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.10a
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• pp.690-695
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• 2004

A new dimension measuring method for the measurement of diameter of an object has been developed using laser triangulation. The 3-D data of an object was calculated from the 2dimensional image information obtained by the laser stripe using the laser triangulation. The system can measure the diameter of hole not only in a normal plane but also in an incline plane. We can experiment with magnification that is optimized according to size of object using zoom lens. In this paper, the theoretical formula and calibration of the system were described. The measuring precision of the system was investigated by experiment.

• Journal of KIISE:Databases
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• v.30 no.5
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• pp.521-531
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• 2003

Multi-level geographic data can be mainpulated by a window query such as a zoom operation. In order to handle multi-level geographic data efficiently, a spatial indexing method supporting a window query is needed. However, the conventional spatial indexing methods are not efficient to access multi-level geographic data quickly. To solve it, other a few spatial indexing methods for multi-level geographic data are known. However these methods do not support all types of multi-level geographic data. This paper presents a new efficient spatial indexing method, the MLR-tree for window query of multi-level geographic data. The MLR-tree offers both high search performance and no data redundancy. Experiments show them. Moreover, the MLR-tree supports all types of multi-level geographic data.

• Proceedings of the KIEE Conference
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• 2005.11a
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• pp.164-167
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• 2005

In this paper, the design and characteristics of a ${\pi}-shaped$ ultrasonic motor which is applicable to optical zoom operation of lenssystem for mobile phone are investigated. Its desi후 and simulation of performances are carried out by FEM (finite element method) commercial software. As a simulation result, by applying voltage with single phase, a combined vibration is produced at the surface of an arm of stator. The prototype of motor is fabricated and its outer size is 8*4*2 $mm^3$ including the cylindrical steel rod of 2 mm in diameter as rotor. The motor exhibits a maximum speed of 500 rpm and a power consumption of 0.3 W when driven at 20 Vpp and 64 kHz.

• Journal of Hospice and Palliative Care
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• v.24 no.4
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• pp.245-253
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• 2021

Purpose: This study aimed to explore the experiences of hospice and palliative care (HPC) nurses at inpatient hospice centers in South Korea during the coronavirus disease 2019 pandemic. Methods: Data collection was conducted through individual interviews with 15 HPC nurses using face-to-face interviews, telephone calls, or Zoom videoconferencing. Data were analyzed using the thematic analysis method. Results: This study found that HPC nurses experienced practical and ethical dilemmas that reinforced the essential meaning and value of hospice and palliative care. The participants emphasized their practical roles related to compliance with infection prevention measures and their roles as rebuilders of hospice and palliative care. Conclusion: The findings of this study indicate that inpatient hospice centers must mitigate the practical and ethical dilemmas experienced by nurses, consider establishing explanation nursing units, and provide education to support nurses' highlighted roles during the pandemic. This study can be used to prepare inpatient hospice centers and the nurses that work there for future infectious disease outbreaks.