• Journal of Korea Water Resources Association
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• v.52 no.spc2
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• pp.865-873
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• 2019

The purpose of this study is to develop and apply a river space restoration framework considering various functions of river basin system. In particular, we will present sustainable river basin management directions by quantifying the effect of improving the aquatic ecosystem through the restoration of river space. For this purpose, the present problems are derived from functional aspects of the river basin, and the river area restoration framework linked with the individual outcome indicators is constructed to evaluate the restoration effect by each function. The ecological impact of restoration of river area was quantitatively analyzed by introducing ecotope concept. As a result of the comparison of restoration effects by creating three kinds of river area restoration scenarios, the construction of suitable habitat such as backswamp in the expanded area has shown favorable results in expanding biodiversity. The diversity evaluation of ecotope in conjunction with the hydraulic and hydrological characteristics of the year will not only provide the expected effects of restoration of river space but will also serve as a criterion about post-project monitoring for outcome evaluation.

• Journal of the Korean Geosynthetics Society
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• v.6 no.3
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• pp.9-16
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• 2007

Soil vapor extraction (SVE) is an effective and cost efficient method of removing volatile organic compounds (VOCs) and petroleum hydrocarbons from unsaturated soils. Incorporating PVDs in an SVE system can extend the effectiveness of SVE to lower permeability soils by shortening the air flow-paths and ultimately expediting contaminant removal. With this approach, the real bounded system is replaced for the purposes of analysis by an imaginary system of infinite areal extent. The boundary conditions for the contaminant remediation model test include constant head and no flow condition. Due to these parallel boundaries conditions, image wells should be developed in order to maintain the condition of no flow across the impermeable boundary. It is also assumed that the flow is drawdown along the constant head boundary condition. The factors contributing to the difference between the theoretical and measured pressure heads were also analyzed. The flow factor increases as the flow rate is increased. The flow rate is the most important factor that affects the difference between the measured and theoretical pressure heads.

• The Transactions of the Korea Information Processing Society
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• v.3 no.4
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• pp.938-946
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• 1996

Hierarchical subband codec has been widely promoted in the field of data compression/decompression because of their simplicity and modular nature. Over the past years, the study has received great attention to the perfect reconstruction (PR)system which perfectly recovers the original input signal at the reconstructed output. However, in the actual subband codec system, the signals that passed through the analysis filter bank are quantized before transmission to the receiver side and reconstructed by the synthesis filter bank. Thus the PR system is impossible and the quantization effects must be carefully considered in the system design such that the system recovers the reconstructed output as possible to the the original input signal with minimum quantization error.In this paper, we propose an optimum hierarchical subband codec structure in the presence of quantizer. The optimality criteria of the code is given to the deign of the hierarchical analysis/synthesis subband filter bank and the quantizer that minimize then output mean square error due to the quantizer in the codec. Specific opti-mum design esamples are shown with level-1, level-2 hierarchical structure. The optimal designs are verified by computer simulation.

• Journal of KIISE
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• v.44 no.8
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• pp.749-759
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• 2017

The weapon system based on voice call can cause delay, error or damage to the message during the exchange of information. Furthermore, since the weapon system has a unique message format, it has limited data distribution. Therefore, a Korea Variable Message Format(KVMF) has been developed in this study to utilize a standard sized data format to guarantee the transmission quality and minimize the transmission amount. The ground tactical data link system quickly and accurately shares tactical information by incorporating a field management system that utilizes the KVMF standard message in the mobile weapon system. In this study, we examine the possibility of performing the mission immediately by recovering the state of network joining when a normal/abnormal termination situation of the battlefield management system occurs.

• Journal of the Korea Society of Computer and Information
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• v.11 no.6 s.44
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• pp.269-277
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• 2006

We propose a new expert system for recovering the broken fragments of relics into an original form using computer graphics and image processing. This paper presents a system with an application to tombstones objects of flat plane with letters carved in for assembling the fragments by placing their respective fragments in the right position. The matching process contains three sub-processes: aligning the front and letters of an object, identifying the matching directions, and determining the detailed matching positions. We apply least squares fitting, vector inner product, and geometric and RGB errors to the matching process. It turned out that 2-D translations via fragments-alignment enable us to save the computational load significantly. Based on experimental results from the damaged cultural fragments, the performance of the proposed method is illustrated.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.40 no.5
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• pp.332-346
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• 2003

In this paper, a system which can compress and reconstruct the digital image was implemented using 2 dimensional DWT(Discrete Wavelet Transform). The proposed system consists of the FPGA board tocompress the image and the application software(S/W) to reconstruct it. First the FPGA receives the image from AID converter and compresses the image using wavelet transform. The compressed data is transferred into the PC using the PCI interface. The compressed image is reconstructed by an application S/W inside the PC. The image compressor can compress about 60 fields per second, in which the image format was NTSC YCbCr(4:2:2) and the image size was 640${\times}$240 pixels per field. The designed hardware mapped into one FPGA occupying 11,120 LAB (Logic Array Block) and 27,456 ESB(Embedded System Block) in APEX20KC EP20K1000B652-7. It globally uses 33MHz clock and the memory control part uses 100MHz.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.10
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• pp.2417-2426
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• 2014

Remote gaze tracking system calculates the gaze from captured images that reflect infra-red LEDs in cornea. Glint is the point that reflect infra-red LEDs to cornea. Recently, remote gaze tracking system uses a number of IR-LEDs to make the system less prone to head movement and eliminate calibration procedure. However, in some cases, some of glints are unable to spot. In this case, it is impossible to calculate gaze. This study examines patterns of glints that are difficult to detect in remote gaze tracking system. Afterward, we propose an algorithm to reconstruct positions of missing glints that are difficult to detect using other detected glints. Based on this algorithm, we increased the number of valid image frames in gaze tracking experiments, and reduce errors of gaze tracking results by correcting glint's distortion in the reconstruction phase.

• 한국공간정보시스템학회:학술대회논문집
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• 2005.05a
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• pp.281-286
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• 2005

여러 분야에서 활용성이 증가하고 있는 도시지역에 대한 3차원 모형화 구축은 기존에는 항공사진이나 고해상도 위성영상을 주로 활용하여 왔으나, 최근에는 높은 정밀도를 보장하는 항공LIDAR 측량기법에 대한 연구가 활발히 진행되고 있다. 특히, 다양한 형태, 크기, 종류의 건물들이 존재하는 광범위한 도시지역을 모형화 하기 위하여 정밀도가 높은 LIDAR 자료를 통하여 신속하고 정확하게 현실에 가까운 건물 모형으로 복원하는 기술 개발이 요구되고 있다. 본 연구에서는 LIDAR 관측자료 및 디지털 영상, 수치지도 등의 자료를 활용하여 LIDAR자료의 전처리 과정과 다양한 필터를 적용하여 지면과 비지면 정보를 분류하였으며, LoG 연산자에 의한 건물 경계선 및 특징점 추출기법을 개발하여 도시 지역의 3차원 건물 복원기법을 제안하였다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.3C
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• pp.245-249
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• 2006

In general, a large number of the memory accesses are required to decode the CAVLC in H.264/AVC. This is a serious problem for applications such as a DMB and videophone services because of the considerable amount of power that is consumed in accessing the memory. In order to overcome this problem, we propose an efficient run_before decoding method, In the proposed method, the memory access is removed by using a FSM with arithmetic operations. The simulation results show that the proposed algorithm does not degrade video quality is not degraded as well as the power is saved.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.36S no.4
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• pp.45-54
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• 1999

본 논문에서는 웨이브렛 변환 대역에서 영역분할 기법을 적용하여 얻어진 각 영역을 중요 영역과 비 중요 영역으로 분류하고 각각의 영역을 그의 특성에 적합한 방식으로 부호화 하는 기법을 제안하였다. 중요 영역은 전체 영역가운데 매우 작은 부분을 차지하지만 영상 복원에 매우 큰 영향을 주기 때문에 이러한 영역 부호화를 위해 기존의 EZW 방식보다 성능이 우수하며 단일계수 전송에 성능이 뛰어난 SPIHT 알고리즘을 적용하였다. 그러나 비 중요영역은 영상복원에 미치는 영향이 적을 뿐만 아니라, 매우 큰 동질 영역을 형성하기 때문에 텍스춰 모델링을 이용할 경우 높은 압축률을 얻을 수 있다. 또한 이 방식을 이용할 경우 인위적인 에러가 거의 없기 때문에 이용할 경우 높은 압축률을 얻을 수 있다. 또한 이 방식을 이용할 경우 인위적인 에러가 거의 없기 때문에 시각적으로도 좋은 영상을 복원 할 수 있다. 실험결과 제안한 시스템은 다양한 영상에 대하여 적응성이 있음을 보였고 특히 0.2bpp 이하의 매우 낮은 비트 율에서도 EZW 와 같은 기존의 웨이브렛 기반 부호화기보다 좋은 성능을 나타내었다.