• Smart Media Journal
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• v.1 no.3
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• pp.15-21
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• 2012

Depth information is necessary for various three dimensional contents generation. Depth acquisition techniques can be categorized broadly into two approaches: active, passive depth sensors depending on how to obtain depth information. In this paper, we take a look at several ways of depth acquirement. We present not only depth acquisition methods using discussed ways, but also hybrid methods which combine both approaches to compensate for drawbacks of each approach. Furthermore, we introduce several matching cost functions and post-processing techniques to enhance the temporal consistency and reduce flickering artifacts and discomforts of users caused by inaccurate depth estimation in 3D video.

• Smart Media Journal
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• v.1 no.3
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• pp.22-28
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• 2012

As the smart media becomes more popular, the demand for high-quality 3D images and depth maps is increasing. However, performance of the current technologies to acquire depth maps is not sufficient. The depth maps from stereo matching methods have low accuracy in homogeneous regions. The depth maps from depth cameras are noisy and have low-resolution due to technical limitations. In this paper, we introduce the state-of-the-art algorithms for depth map enhancement and up-sampling from conventional methods using only depth maps to the latest algorithms referring to both depth maps and their corresponding color images. We also present depth map enhancement algorithms for hybrid camera systems in detail.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2000.11b
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• pp.300-306
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• 2000

This paper introduces a new concept of automation for bio-production with tele-operative system. The proposed system showed practical and feasible way of automation for the volatile bio-production process. Based on the proposition, recognition of the job environment with object identification was performed using computer vision system. A man-machine interactive hybrid decision-making, which utilized a concept of tele-operation was proposed to overcome limitations of the capability of computer in image processing and feature extraction from the complex environment image. Identifying watermelons from the outdoor scene of the cultivation field was selected to realize the proposed concept. Identifying watermelon from the camera image of the outdoor cultivation field is very difficult because of the ambiguity among stems, leaves, shades, and especially fruits covered partly by leaves or stems. The analog signal of the outdoor image was captured and transmitted wireless to the host computer by R.F module. The localized window was formed from the outdoor image by pointing to the touch screen. And then a sequence of algorithms to identify the location and size of the watermelon was performed with the local window image. The effect of the light reflectance of fruits, stems, ground, and leaves were also investigated.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.23 no.6
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• pp.636-641
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• 2014

This paper discusses the fabrication process for a Nipkow disk using micro-lens and pinhole disks. The confocal measuring system that uses the Nipkow disk has the advantage in measuring speed, because the Nipkow disk can simultaneously provide confocal images of all pixels in a CCD camera without requiring a lateral scanning unit. A micro-lens configuration, which focuses illumination on a pinhole, overcomes the low optical efficiency of the Nipkow disk system and allows its use in practical applications. This paper describes how to design the Nipkow disk in terms of numerical aperture, particularly for measuring the height of solder bumps in packaging application and for hybrid processes combining mechanical and semiconductor processes.

• ETRI Journal
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• v.37 no.4
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• pp.752-765
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• 2015

We propose a novel post-processing algorithm and its very-large-scale integration architecture that simultaneously uses the passive and active stereo vision information to improve the reliability of the three-dimensional disparity in a hybrid stereo vision system. The proposed architecture consists of four steps - left-right consistency checking, semi-2D hole filling, a tiny adaptive variance checking, and a 2D weighted median filter. The experimental results show that the error rate of the proposed algorithm (5.77%) is less than that of a raw disparity (10.12%) for a real-world camera image having a $1,280{\times}720$ resolution and maximum disparity of 256. Moreover, for the famous Middlebury stereo image sets, the proposed algorithm's error rate (8.30%) is also less than that of the raw disparity (13.7%). The proposed architecture is implemented on a single commercial field-programmable gate array using only 13.01% of slice resources, which achieves a rate of 60 fps for $1,280{\times}720$ stereo images with a disparity range of 256.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.29 no.2
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• pp.8-18
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• 2015

This paper proposes a dimming method and a hybrid LED driving circuit suitable for the ultra high definition (UHD) broadcasting. There are major two problems during the dimming control for traditional LED broadcast lightings; one is a flicker that occurred when camera filming to these lightings, and the other is that linear control is impossible for LED luminous intensity under 10% due to LED electrical characteristics. The proposed dimming method and the driving circuit are designed to solve two problems simultaneously. For high level dimming control region from 10 to 100%, the analog control method was applied to the switching regulator constructed by MOSFET operated in the saturation region. For low level dimming control region under 10%, the fast PWM control method with the linear regulator constructed by MOSFET in the ohmic region was used. We verified experimentally that the dimming method is able to control the luminous intensity linearly from 1 to 100% and the flicker disappears on images taken by the charge coupled device (CCD) and the complementary metal oxide semiconductor (CMOS) cameras. Therefore, the proposed method is suitable for the UHD broadcasting.

• The Journal of the Korea Contents Association
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• v.3 no.2
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• pp.24-30
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• 2003

Pre-existing authentication system such as token based method, knowledge-based and hybrid method have problems such as loss and wiretapping. for this, this paper describes the biometric authentication system which have the excellent convenience and security. In particular, a new biometric system by human face biometric features which have the non-enforcement and non-touch measurement is proposed. Firstly, facial features are extracted by Y- histogram and tilted face images we corrected by coordinate transformation and scaling has done for achieving independent of the camera positions. Secondly, feature vectors are extracted such as distance and intersection angles and similarities we measured by fuzzy relation matrix. finally, the effectiveness of this paper is demonstrated by experiments.

• Journal of Sensor Science and Technology
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• v.32 no.2
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• pp.124-130
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• 2023

Implementing flexible production systems in domestic and foreign automotive design parts assembly has increased demand for automation and power reduction. Consequently, transition to a hybrid production method is observed where multiple vehicles are assembled in a single assembly line. Multiple robots, 3D vision sensors, mounting positions, and correction software have complex configurations in the automotive glass mounting system. Hence, automation is required owing to significant difficulty in the assembly process of automobile parts. This study presents a primer lighting and inspection algorithm that is robust to the assembly environment of real automotive design parts using high power 'ㄷ'-shaped LED inclined lighting. Furthermore, a 2D camera was developed in the primer coating inspection system-the core technology of the glass mounting system. A primer application demo line applicable to the actual automobile production line was established using the proposed high power lighting and algorithm. Furthermore, application inspection performance was verified using this demo system. Experimental results verified that the performance of the proposed system exceeded the level required to satisfy the automobile requirements.

• Journal of Digital Convergence
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• v.10 no.10
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• pp.333-338
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• 2012

Human resource management is bringing the various changes with the IT technology. In particular, if HRM is non-scientific method such as group management, physical plant, working hours constraints, personal contacts, etc, the current enterprise human resources management(e-HRM) appeared in the individual dimension management, virtual workspace (for example: smart work center, home work, etc.), working time flexibility and elasticity, computer-based statistical data and the scientific method of analysis and management has been a big difference in the sense. Therefore, depending on changes in the environment, companies have introduced a variety of techniques as RFID card, fingerprint time & attendance systems in order to build more efficient and strategic human resource management system. In this paper, time and attendance, access control management system was developed using multi camera for 2D and 3D face recognition technology-based for efficient enterprise human resource management. We had an issue with existing 2D-style face-recognition technology for lighting and the attitude, and got more than 90% recognition rate against the poor readability. In addition, 3D face recognition has computational complexities, so we could improve hybrid video recognition and the speed using 3D and 2D in parallel.

• Nuclear Engineering and Technology
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• v.54 no.11
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• pp.4102-4110
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• 2022

Aiming at high-power and long-pulse operation up to 1000 s, some improvements have been made for both 2.45 GHz and 4.6 GHz lower hybrid (LH) systems during the recent 5 years. At first, the guard limiters of the LH antennas with graphite tiles were upgraded to tungsten, the most promising material for plasma facing components in nuclear fusion devices. These new guard limiters can operate at a peak power density of 12.9 MW/m². Strong hot spots were usually observed on the old graphite limiters when 4.6 GHz system operated with power >2.0 MW [B. N. Wan et al., Nucl. Fusion 57 (2017) 102019], leading to a reduction of the maximum power capability. With the new limiters, 4.6 GHz LH system, the main current drive (CD) and electron heating tool for EAST, can be operated with power >2.5 MW routinely. Long-pulse operation up to 100 s with 4.6 GHz LH power of 2.4 MW was achieved in 2021 and the maximal temperature on the guard limiters measured by an infrared (IR) camera was about 540 ℃, much below the permissible value of tungsten material (~1200 ℃). A discharge with a duration of 1056 s was achieved and the 4.6 GHz LH energy injected into the plasma was up to 1.05 GJ. Secondly, the fully-active-multijunction (FAM) launcher of 2.45 GHz system was upgraded to a passive-active-multijunction (PAM), for which the density of optimum coupling was relatively low (below the cut-off value). Good coupling with reflection coefficient ~3% has been achieved with plasma-antenna distance up to 11 cm for the new PAM. Finally, in order to eliminate the effect of ion cyclotron range of frequencies (ICRF) wave on 4.6 GHz LH wave coupling, the location of the ICRF launcher was changed to a port that is located 157.5° toroidally from the 4.6 GHz LH system and is not magnetically connected.