• Korean Journal of Optics and Photonics
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• v.17 no.1
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• pp.47-53
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• 2006

The Integrated Ballistics Identification Systems (IBIS) is widely used for bullet and casing signature identification. The IBIS obtains a pair of ballistic signatures from two bullets (or casings) using optical microscopy, and estimates a correlation score which can represent the degree of signature match. However, this method largely depends on lighting and surface conditions because optical image contrast is primarily a function of test surface's slope, shadowing, multiple reflections, optical properties, and illumination direction. Moreover, it can be affected with surface height variation. To overcome these problems and improve the identification system, we used well known surface topographic techniques, such as confocal microscopy and white-light scanning interferometry. The measuring instruments were calibrated by a NIST step height standard and verified by a NIST sinusoidal profile roughness standard and a commercial roughness standard. We also suggest a new analysis method for the ballistic identification. In this method, the maximum cross-correlation function CCFmax is used to quantify the degree of signature match. If the compared signatures were exactly the same, CCFmax would be $100\%$.

• Journal of Broadcast Engineering
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• v.17 no.4
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• pp.611-624
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• 2012

'Gesture' is the most intuitive means of communication except the voice. Therefore, there are many researches for method that controls computer using gesture input to replace the keyboard or mouse. In these researches, the method of user detection and main body parts estimation is one of the very important process. in this paper, we propose user objects detection and main body parts estimation method on inaccurate depth information for pose estimation. we present user detection method using 2D and 3D depth information, so this method robust to changes in lighting and noise and 2D signal processing 1D signals, so mainly suitable for real-time and using the previous object information, so more accurate and robust. Also, we present main body parts estimation method using 2D contour information, 3D depth information, and tracking. The result of an experiment, proposed user detection method is more robust than only using 2D information method and exactly detect object on inaccurate depth information. Also, proposed main body parts estimation method overcome the disadvantage that can't detect main body parts in occlusion area only using 2D contour information and sensitive to changes in illumination or environment using color information.

• The KIPS Transactions:PartB
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• v.11B no.3
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• pp.327-336
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• 2004

For visual inspection system in real industrial environment, it is one of most important tasks to design fast and stable pattern matching algorithm. This paper presents an edge-based point correlation algorithm avoiding full search in visual inspection system. Conventional algorithms based on NGC(normalized gray-level correlation) have to overcome some difficulties for applying to automated inspection system in factory environment. First of all, NGC algorithms need high time complexity and thus high performance hardware to satisfy real-time process. In addition, lighting condition in realistic factory environments if not stable and therefore intensity variation from uncontrolled lights gives many roubles for applying directly NGC as pattern matching algorithm in this paper, we propose an algorithm to solve these problems from using thinned and binarized edge data and skipping full point search with edge-map analysis. A point correlation algorithm with the thinned edges is introduced with image pyramid technique to reduce the time complexity. Matching edges instead of using original gray-level pixel data overcomes NGC problems and pyramid of edges also provides fast and stable processing. All proposed methods are preyed from experiments using real images.

• Journal of Broadcast Engineering
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• v.24 no.3
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• pp.463-471
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• 2019

This paper proposes a method for reducing the complexity of LIC (Local Illuminance Compensation) for bi-directional inter prediction. The LIC performs local illumination compensation using neighboring reconstruction samples of the current block and the reference block to improve the accuracy of the inter prediction. Since the weight and offset required for local illumination compensation are calculated at both sides of the encoder and decoder using the reconstructed samples, there is an advantage that the coding efficiency is improved without signaling any information. Since the weight and the offset are obtained in the encoding prediction step and the decoding step, encoder and decoder complexity are increased. This paper proposes two methods for low complexity LIC. The first method is a method of applying illumination compensation with offset only in bi-directional prediction, and the second is a method of applying LIC after weighted average step of reference block obtained by bidirectional prediction. To evaluate the performance of the proposed method, BD-rate is compared with BMS-2.0.1 using B, C, and D classes of MPEG standard experimental image under RA (Random Access) condition. Experimental results show that the proposed method reduces the average of 0.29%, 0.23%, 0.04% for Y, U, and V in terms of BD-rate performance compared to BMS-2.0.1 and encoding/decoding time is almost same. Although the BD-rate was lost, the calculation complexity of the LIC was greatly reduced as the multiplication operation was removed and the addition operation was halved in the LIC parameter derivation process.

• KIPS Transactions on Software and Data Engineering
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• v.10 no.3
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• pp.99-108
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• 2021

There are unrestricted conditions on the driver's face inside the vehicle, such as changes in lighting, partial occlusion and various changes in the driver's condition. In this paper, we propose a face identification system in an unrestricted vehicle environment. The proposed method uses a near-infrared (NIR) camera to minimize the changes in facial images that occur according to the illumination changes inside and outside the vehicle. In order to process a face exposed to extreme light, the normal face image is changed to a simulated overexposed image using mean and variance for training. Thus, facial classifiers are simultaneously generated under both normal and extreme illumination conditions. Our method identifies a face by detecting facial landmarks and aggregating the confidence score of each landmark for the final decision. In particular, the performance improvement is the highest in the class where the driver wears glasses or sunglasses, owing to the robustness to partial occlusions by recognizing each landmark. We can recognize the driver by using the scores of remaining visible landmarks. We also propose a novel robust rejection and a new evaluation method, which considers the relations between registered and unregistered drivers. The experimental results on our dataset, PolyU and ORL datasets demonstrate the effectiveness of the proposed method.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.46 no.3
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• pp.112-118
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• 2009

Skin color segmentation techniques have been widely utilized for face/hand detection and tracking in many applications such as a diagnosis system using facial information, human-robot interaction, an image retrieval system. In case of a video image, it is common that the skin color model for a target is updated every frame for the robust target tracking against illumination change. As for a single image, however, most of studies employ a fixed skin color model which may result in low detection rate or high false positive errors. In this paper, we propose a novel method for effective skin color segmentation in a single image, which modifies the conditions for skin color segmentation iteratively by the image feedback of segmented skin color region in a given image.

• Journal of the Korea institute for structural maintenance and inspection
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• v.23 no.7
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• pp.33-39
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• 2019

In this study, an experimental study was carried out with variables of the shape of the ground soil-binder in order to find out whether the shear wave velocity and the ground grade were improved by the ground improvement. In this study, the shear wave velocity was measured using the crosshole method with variables of the shape of the ground soil-binder. In addition, the prediction formula of the shear wave velocity for suitability of N-Values for the domestic soil conditions are proposed using the result value of this study and the existing results of shear wave velocity. As a result, the shear wave velocity of the ground has increased. In addition, the prediction formula proposed in this study reasonably issued the existing experimental results regardless of the stratum conditions.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.17 no.5 s.108
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• pp.451-460
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• 2006

We have designed local exposure systems for long-time mice experiments in PCS and cellular frequency band(PCS: 1,762.5 MHz, cellular: 848.5 MHz). The fabricated systems are local exposure systems of carousel type, and 40 mice can be exposed at a time. In order not to give extra stress to the mice ender experiment, the systems were fabricated to meet the environmental conditions such as illumination, ventilation, noise etc. SAR measurement was performed using a temperature probe. Measurements at 3 points in the head of mouse cadaver and solid phantom were made, and it has been confirmed that the measurement results are in good agreement with the simulation results in the real exposure environment. The exposure systems are currently used for long-term mice experiments.

• Archives of design research
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• v.16 no.4
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• pp.323-334
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• 2003

This study examines the multi-functionality of the cultural facilities and explores the architectural characteristics of cultural facilities in city environment. For this purpose, 1 examine the major cultural facilities in USA and Singapore. Recently, the inter-cultural communication methods have been diversified and the cultural facilities need to be designed to effectively accommodate the public's interests in these activities. It is also necessary to reexamine cultural facilities' functions in terms of how the multi-functionality facilities reflect the surrounding environment. This study also sheds a new light on the meaning of the relationships between cultural activity, and the cultural facility design. For this, I primarily look at the various design categories of cultural buildings and their main functions. Finally, I demonstrate how both cultural activity and cultural facility design elements are embodied in the city environment.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.538-539
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• 2013

여러 장점으로 인해 OLED는 디스플레이 및 조명 등 적용분야가 넓어지고 있지만, 수분 및 산소에 취약하여 그 수명이 제한되는 단점이 있다. 이를 해결하고자 현재까지는 glass cap을 이용한 encapsulation 기술이 적용되고 있지만, flexible 기판에 적용하지 못하는 문제가 있다. 이러한 문제를 해결하고자 여러 가지 thin film encapsulation 기술이 적용되고 있으나 보다 신뢰성이 높은 기술의 개발이 절실한 때이다. Encapsulation 무기 박막 물질로서 $Si_3N_4$ 박막은 PE-CVD (Plasma Enhanced Chemical Vapor Deposition) 등의 박막 증착법을 사용한 많은 연구가 진행되어, 저온에서의 좋은 품질의 박막 증착이 가능하지만, 100도 이하의 thermal budget을 갖는 OLED Encapsulation에 사용하기에는 충분하지 않았다. CVD 박막의 특성을 더욱 개선하기 위해 최근 ALD (Atomic Layer Deposition) 방법을 통한 $Al_2O_3$ film 증착 방법이 연구되고 있지만, 낮은 증착 속도로 인해 양산에 걸림돌이 되고 있다. 본 연구에서는 또 다른 해결책으로서 Digital CVD 방법을 이용한 양질의 $Si_3N_4$ 박막의 증착을 연구하였다. 이것은 ALD 증착법과 유사하며, 1st step에서 PECVD 방법으로 4~5 ${\AA}$의 얇은 silicon 박막을 증착하고, 2nd step에서 nitrogen plasma를 이용하여 질화 반응을 진행하고, 이러한 cycle을 원하는 두께가 될 때까지 반복적으로 진행된다. 이 때 1 cycle 당 증착속도는 7 ${\AA}$/cycle 정도였다. 최적의 증착 방법과 조건으로 기존의 CVD $Si_3N_4$ 박막 대비 1/5 이하로 pinhole을 최소화 할 수는 있지만 완벽하게 제거하기는 힘든 문제가 있고, 이를 해결하기 위한 개선을 위한 접근 방법이 필요하다고 판단하였다. 본 연구에서는 무기물 박막인 carbon nitride를 이용한 SiN/C:N multilayer 증착 연구를 진행하였다. Fig. 1은 CVD 조건으로 증착된 두께 750 nm SiN film에서 여러 층의 C:N film layer를 삽입했을 때, 38 시간의 85%/$85^{\circ}C$ 가속실험에 따라 OLED의 발광 사진이다. 그림에서 볼 수 있듯이 C:N 층을 삽입하고 또한 그 박막의 수가 증가함에 따라서 OLED에 대한 encapsulation 특성이 크게 개선됨을 확인할 수 있다.