• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2009.11a
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• pp.87-90
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• 2009

영상의 깊이 정보를 추출하는 것은 매우 어려운 연구이다. 다양한 유형의 영상 구조의 분석이 필요하지만 많은 경우에 주관적인 판단의 도움이 필요하다. 본 논문에서는 로스 텍스처 필터를 기반으로 정지 영상의 깊이를 자동으로 생성하는 방법을 제안한다. 로스 텍스처 필터는 단안 비전에서 3D 깊이를 얻기 위한 방법으로 활용되었는데, 실제 2D 영상에서 깊이를 예측하기 위해 텍스처 편차, 텍스처 기울기, 색상 등을 활용한다. 로스 필터는 $1{\times}5$ 벡터로부터 콘볼루션을 이용하여, 20여개의 $5{\times}5$ 콘볼루션 필터가 구해지는데, 영상에 필터를 적용하여 로스 에너지를 계산한다. 구해진 에너지를 깊이 맵으로 변환하고, 깊이 맵에서 특징 점을 구하고, 특징 점들로부터 델러노이 삼각화를 이용하여 삼각형 깊이 메쉬를 얻는다. 구해진 깊이 맵의 성능을 측정하기 위해 카메라 시점을 변경하면서 영상의 3D 구조를 분석하였으며, 입체영상을 생성하여 3D 입체 시청 결과를 분석하였다. 실험에서는 로스 텍스처 필터를 이용하는 깊이 생성 방법이 좋은 효과를 얻는 것을 확인하였다.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2012.11a
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• pp.25-28
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• 2012

본 논문에서는 키넥트(Kinect)에서 획득한 깊이 영상의 품질을 향상시키는 기법을 제안한다. 키넥트는 마이크로소프트사에서 출시한 카메라로 깊이 영상과 컬러 영상을 획득 할 수 있다. 하지만 적외선 패턴을 이용한 깊이 영상의 획득 방법의 한계로 인해 객체의 경계 주변으로 홀 및 잡음이 생긴다. 따라서 정확한 깊이 영상을 얻기 위해서는 깊이 영상의 품질 향상이 필수적이다. 일반적으로 깊이 영상의 홀을 채울 때, 인페인팅(inpainting) 또는 결합형 양방향 필터(joint bilateral filter) 등의 기법을 사용한다. 그러나 이러한 기법들의 경우 한 장의 영상만을 이용하기 때문에 객체 경계 주변의 흔들림 현상을 보정할 수 없다. 제안하는 기법에서는 먼저 수행속도가 빠른 가우시안 필터를 이용하여 경계 주변의 홀을 채운다. 이전 프레임의 컬러 영상을 그레이 영상으로 변환한 다음에 그레이 영상과 깊이 영상의 값의 변화를 분석하여 흔들림 화소를 찾아 이전 깊이 영상들 중 최대 화소 값으로 변환함으로써 깊이 영상의 경계 흔들림 현상을 줄일 수 있다. 실험을 통해 제안하는 기법이 기존의 방법들 보다 우수하다는 것을 확인하였다.

• Journal of Broadcast Engineering
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• v.20 no.2
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• pp.224-237
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• 2015

In this paper, we introduce the fast decoding method with the SIMD (Single Instruction Multiple Data) instructions for HEVC RExt (High Efficiency Video Coding Range Extensions). Several tools of HEVC RExt such as intra prediction, interpolation, inverse-quantization, inverse-transform, and clipping modules can be classified as the proper modules for applying the SIMD instructions. In consideration of bit-depth increasement of RExt, intra prediction, interpolation, inverse-quantization, inverse-transform, and clipping modules are accelerated by SSE (Streaming SIMD Extension) instructions. In addition, we propose effective implementations for interpolation filter, inverse-quantization, and clipping modules by utilizing a set of AVX2 (Advanced Vector eXtension 2) instructions that can use 256 bits register. The evaluation of the proposed methods were performed on the private HEVC RExt decoder developed based on HM 16.0. The experimental results show that the developed RExt decoder reduces 12% average decoding time, compared with the conventional sequential method.

• Journal of The Korean Society of Agricultural Engineers
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• v.60 no.1
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• pp.31-36
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• 2018

A rainwater harvesting device was developed for runoff flow harvesting in a small stream or channel and its performance was evaluated in small fields. The rainwater harvesting device has slits on its side of cylindrical volume in 15 cm diameter and 70 cm length, which is designed to increase its water flow harvesting capacity. The maximum collectable water quantity was about 0.0022 ton/sec (130 L/min). Rainwater harvesting device were installed in two locations (P1, P2). P1 is a point for rainfall runoff flow harvesting. P2 is a point for ordinary flow harvesting. During this study, total rainfall depth was 334.5 mm. Runoff of 1,722 ton and 7,984 ton occurred in P1 and P2, and 273 ton and 125 ton were collected by this rainwater harvesting device. Harvesting efficiency was calculated as 15.85 % and 1.57 % in P1 and P2. Clogging of screen filter media in the cylinder due to soil and suspended solids has lowered the harvesting efficiency. However, it was possible to harvest 30 ton/month of rainwater harvesting and it is expected that it will help to solve short-term water shortage.

• The Journal of Engineering Geology
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• v.30 no.4
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• pp.603-615
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• 2020

The design factors of artificial recharge are determined by considering the hydrogeological characteristics of the aquifer. The optimal design factors for artificial recharge were derived after performing the injection tests step by step for each injection type (vertical well, ditch and mixed type), which were built in the test site of the study area. It was analyzed that the difference in the injection effect according to the diameter of the injection well was not large, and the 100 mm well was evaluated as appropriate in consideration of the availability and economy of land use. Since the injection effect was well maintained even in the upper rock, the depth of the injection well was proposed for the alluvial layer and the upper rock layer. On the other hand, in four cases of filter media in the ditch, it was analyzed that the penetration efficiency and the hydraulic interference effect indicated excellent injection performance when a filter medium of 10 to 30 mm diameter was filled in the ditch. In addition, the proper spacing of the injection wells was analyzed as 9~12 m considering the interference efficiency. The interference efficiency attenuation coefficient per 1 m of hole spacing was calculated to be 1.75% in this area. In the future study, the artificial recharge design factors obtained in this stage are applied and verified on site construction and operation. Also it is expected to contribute to securing water in areas where there is always a lack of water.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.5
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• pp.895-905
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• 2000

This study was performed to investigate the removal efficiencies of pollutants at various filtration rates and the quality of the filtered water along the depth of filter media during treatment of a BNR process effluent by a dual-media gravitational rapid filtration. The results of the experiments at filtration rates of 200, 300 and 400 m/day using the effluent of a pilot scale 4-stage BNR plant showed that turbidity of the filtered water was below 2.6 NTU, satisfying the Korean standard for water for reuse. Even though the SS removal efficiency deteriorated as the filtration rate increased, the average SS concentration of the filtered water was 1.3 mg/L at all filtration rates. Simultaneous biological nitrification and denitrification was observed with nitrification efficiencies of 17.4, 18.8 and 14.3%, and denitrification efficiencies of 32.3, 27.7 and 21.4% respectively at filtration rates of 200, 300 and 400 m/day. At the latter period of each filtration cycle, the effluent T-P concentration was higher than influent T-P concentration by 6.1 to 21.4% due to phosphorous release under DO-deficient condition.

• Korean Journal of Environmental Agriculture
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• v.27 no.3
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• pp.217-224
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• 2008

To obtain optimum configuration, depth and load of constructed wetlands(CWs) for treating of hydroponic waste solution(HWS) which was produced in greenhouses, the study was conducted with 4 kinds of combined systems such as Vertical flow(VF)-Horizontal flow(HF), VF-VF, HF-VF and HF-HF CWs. In four configurations of CWs, the treatment efficiency of pollutants from HWS under depth of HF and VF beds, HWS loading and HWSs were investigated. Removal rate of pollutants under different depth of VF and HF in 2-stage hybrid CWs was in the order of 50 cm < 70 cm regardless of CWs configuration. Removal rate of pollutants under HWS loading in 2-stage hybrid CWs was in the order of $150L\;m^{-2}\;day^{-1}{\fallingdotseq}300L\;m^{-2}\;day^{-1}\;>\;450L\;m^{-2}\;day^{-1}$. The optimum depth and HWS loading were 70 cm and $300L\;m^{-2}\;day^{-1}$ in four configurations of CWs, respectively. Using this optimum condition, for various HWSs (cucumber, paprika and strawberry HWS), removal rate of pollutants in HF-HF CWs was higher than that in HF-VF CWs. Optimum configuration of 2-stage hybrid CWs for treating hydroponic waste solution in greenhouses was found out to be HF-HF CWs. Therefore, under the optimum conditions, removal rate of BOD, COD, SS, T-N and T-P in HF-HF CWs were 84, 81, 84, 51 and 93%, respectively.

• Journal of Korean Society on Water Environment
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• v.33 no.1
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• pp.1-7
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• 2017

Bioretention systems, an advance low impact development and green infrastructure approach were currently utilized in different parts of the world because it promotes biodiversity thereby mimicking and preserving the pre-developed state of an area. This study investigated and compared the capability of four bioretention systems to identify factors affecting the hydraulic capabilities and pollutant removal efficiencies of each system. The two bioretention type A referred as Type A-C and Type A-FC were planted with perennials such as Chrysanthemum and Fan columbine, respectively. On the other hand, the two type B bioretention systems referred as Type B-A and Type B-JM were planted with shrub plant species such as Azalea and Japanese Meadowsweet, respectively. Based on the results, TV, infiltration mechanism, filter media depth and plant species were identified as the factors affecting the difference in flow attenuation, retained volume and pollutant removal efficiency of Type A-C, Type A-FC, Type B-A and Type B-JM bioretention systems. The design of bioretention Type B-A and Type B-JM were advantageous considering greater volume retention, groundwater recharge, longer HRT and peak flow attenuation and greater pollutant removal efficiency. On the other hand, the design of bioretention Type A-C and Type A-FC was more appropriate for design considering reduced groundwater contamination.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.49 no.1
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• pp.88-96
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• 2012

According to development of technology for media, observers try to watch the realities from images, as follows, 3D imaging has been extremely developed. 3D image gives depth in the image, observers feel in nature. Different image perception from left and right eyes make the 3D image. Anaglyph which is one of the ways to make an image of three dimensions is for obtaining an image of three dimensions by using color filter glasses. Anaglyph has a little amount of calculation and is easy to make, and it has a good point that anaglyph can be used in more wide field because it can create an image of three dimensions to the output of print like printed matter. However, the phenomenon of retinal rivalry can cause a feeling of fatigue because a difference of brightness of the left image and the right image happen. The way to reduce this problem is made by cutting down a difference of brightness. In the result, retinal rivalry can be reduced. We reduced a difference of the brightness of the left and the right image by utilizing the brightness and average of the original image to reduce retinal rivalry and we made better colors of anaglyph by using the way that we keep the hue caused by a change of brightness and supplement saturation about color distortion which is created at that time.