• Journal of the Korean Society of Groundwater Environment
• /
• v.5 no.2
• /
• pp.110-115
• /
• 1998

In this paper, the sensitivity of the leachate level is analyzed using the program HELP to reduce the high leachate level on the landfill. Hydraulic parameters analyzed were porosity, field capacity, wilting point and initial water content of cover soil and waste. Also, the influence of the difference between the initial water content and the field capacity on the leachate level in the landfill was analyzed. The results of the sensitivity analysis show that the increase of the porosity and the wilting point decreases the leachate level, while the increase of the field capacity and the hydraulic conductivity increases the leachate level. Major parameters to the change of the leachate level were the hydraulic conductivity in the case of cover soil and the porosity, the field capacity and the initial water content in the case of waste.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
• /
• 1999.04a
• /
• pp.88-89
• /
• 1999

• Proceedings of the Korea Information Processing Society Conference
• /
• 2003.11c
• /
• pp.1885-1888
• /
• 2003

본 논문에서는 인쇄물의 위조방지를 위해 에러에 강한 디지털 워터마킹을 제안한다. 제안한 알고리즘은 워터마크 삽입을 위해 먼저 원영상을 웨이브릿 변환하여 근사(approximation) 이미지를 얻고, 워터마크는 근사 이미지의 DC계수를 제외한 중요한 DCT계수에 삽입된다. 워터마크의 강건도 향상을 위해 에러정정코드와 반복을 적용하고, 디지털 기기사이의 변환에 의한 차이를 줄이기 위해 CIE Lab 칼라 공간을 사용하였다. 표준 칼라 영상을 사용하여 실험한 결과, 기존 방법에 비하여 적은 반복으로도 비트에러가 발생을 감소하였으며, 알고리즘은 1차의 프린트 스캔에서는 robust 하고 2차의 프린트 스캔에서는 fagile 한 성격을 나타내었다, 본 알고리즘은 여권, 지폐, 신분증, 면허증등과 같은 인쇄물의 위조방지에 이용될 수 있다.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.6 no.2
• /
• pp.364-370
• /
• 2002

A banknote counter is a machine that automates counting the money in some agencies to treat much banknotes as well as general banking agencies. The banknote counter materialized in this paper is the machine that adds the function of banknote sorting, detecting plural banknote and detecting counterfeit banknote to an existing banknote counter. The technique of sensor signal processing are used for banknote sorting. The technique of sensor application and data processing are used for detecting counterfeit banknote. The technique of precision equipment design and microprocessor application are used for high speed count. Software improved in debugging and difficulties to link with additional hardware. It was materialized through effective control algorithm and real-time signal processing with C-language on the basis of RTOS(real-time operating system) Photodiode, its applications and a magnetic resistance sensor are used as a sensor device with regard to hardware cost -cutting and process velocity. PCF80C552-24 of Philips using Intel I8051 core is used as a control microprocessor. As the results so far achieved, counterfeit banknotes made by the use of a color duplicator and a color Printer, are distinguished from real banknotes through mixing an optical with a magnetic sensor. and, in case that there are some different banknotes while counting, it is prevented for them to be counted without discriminating from the same kind of banknotes in addition to the fu notion of banknote sorting.

• Proceedings of the Korean Information Science Society Conference
• /
• 2003.04c
• /
• pp.328-330
• /
• 2003

홍채 인식 시스템의 성능향상을 위해서는 전처리 단계에서 위조된 데이터나 잡음이 섞인 데이터를 걸러내는 과정이 매우 중요하다. 이 논문에서는, 강인한 홍채 인식 시스템을 위해서 두 단계로 이루어진 눈 영상 검사 알고리즘을 제안한다. 알고리즘의 첫 번째 단계에서는 동공 반지름과 눈꺼풀 움직임 변화량의 상관계수(coefficient)와 2차원 고속 퓨리에 변환(Fast Fourier Transform) 스펙트럼을 이용해 위조된 데이터를 찾아낸다. 두 번째 단계에서는 눈 영상에 눈 깜박임이나 속눈썹의 홍채영역 침범, 홍채 영상이 부분적으로 잘렸을 경우 등의 시스템의 성능저하의 원인이 되는 부적절한 데이터를 찾아낸다. 111영의 1734개의 눈 영상을 대상으로 실험한 결과, 제안된 알고리즘의 성공률은 96.5%였고 이러한 전처리 과정을 통해서 전체적인 시스템의 정확률을 향상시킬 수 있다.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2003.11a
• /
• pp.309-312
• /
• 2003

홍채 인식 시스템의 성능 향상을 위해서는 전처리 단계에서 위조된 데이터나 잡음이 섞인 데이터를 걸러내는 과정이 매우 중요하다. 이 논문에서는 먼저, 효율적인 홍채 인식 시스템을 위한 두 단계의 눈 영상 검사 알고리즘을 제안한다. 알고리즘에서는 동공 반지름과 눈꺼풀 움직임 변화량의 상관계수(coefficient)를 이용해 위조된 데이터를 찾아낸다. 다음으로 양쪽 눈의 홍채 영상을 합쳐서 만들어진 홍채 데이터를 사용한 성능 향상을 실험한다. 특징 추출에는 wavelet transform을, 인식에는 SVM을 사용하였다. 이러한 전처리 과정과 인식 알고리즘을 통해서 전체적인 시스템의 정확률을 향상시킬 수 있다.

• Korean Journal of Soil Science and Fertilizer
• /
• v.22 no.1
• /
• pp.53-60
• /
• 1989

The results of the investigation on the effects of plant nutrio-physiological status and reemergence of sudden wilting in rice on the occurrence of sudden wilting were summarized as follows: 1. The occurrence of sudden wilting, degree of damage and occurring time in the investigated variety showed to concur with the results of the previous experiment. 2. Nitrogen and Potassium contents in leaves related an occurrence of sudden wilting at heading stage have a very high negative co-relation (the value is -0.9224 at Yushin and -0.8243 at Milyang 23). 3. Regarding the relation between occurrence of sudden wilting and root activity capacity at the late growth stage, the root activity capacity at productive growth stage showed higher than at reproductive growth stage, which is the same in the two varieties but Milyang 23 is higher than Yushin. It is confirmed that root activity capacity in the two varieties has become very low at reproductive growth stage. 4. The toot activity capacity in the field with potassium showed a small occurrence of sudden wilting and the root activity capacity in the field with no potassium showed a very high co-relation value (the value is 0.8947 at Yushin and 0.7301 at Milyang 23). 5. Regarding the relation between the occurrence of sudden wilting and water evaporation quantity, water evaporation quantity after the heading date has a more direct relation to sudden wilting than that which occurrs prior to the heading date. Water evaporation quantity is higher in the field with no potassium, low leaves and Yushin, than in the field with potassium high leaves and Milyang 23. 6. The starch content in culm of Yushin and Milyang 23 at ripening stage showed high value in proportion to potassium quantity, and the starch content is lower as internode is lower. However, in fourth internode, the starch content is greatly increased in the field with potassium contrasted to the field with no potassium.

• Korean Journal of Agricultural and Forest Meteorology
• /
• v.16 no.4
• /
• pp.267-273
• /
• 2014

This study is to compare drought-resistance and to find the permanent wilting coefficient of Syringa Dilatata, Euonymus Japonica, Ligustrum Obtusifolium, Nandina Domestica, which are commonly used for rooftop garden due to their relatively strong drought resistance To compare the drought resistance precipitation was blocked from June 4, 2013 to July 20, 2013. During this time, the relative water content, specific electrical conductance, and water potential were measured every seven days and permanent wilting coefficients were investigated. Two days after precipitation was blocked, the relative water content in leaves were measured as follows: Ligustrum Obtusifolium 91.3%, Syringa Dilatata 92.9%, Nandina Domestica 91.2%, and Euonymus Japonica 90.1% respectively. After 28 days, relative water contents of leaves were reduced greatly 60.2% for Ligustrum Obtusifolium and 67.8% for Syringa Dilatata, but Nandina Domestica and Euonymus Japonica's reduced to 80.1% and 81.7% respectively. Permanent wilting coefficient was Ligustrum Obtusifolium 3.1%, Syringa Dilatata 2.1%, Nandina Domestica 1.6% and Euonymus Japonica 0.7%. In other words, the above four tree species are strong in drought resistance and Euonymus Japonica's drought resistance is the strongest while Nandina Domestica, Syringa Dilatata, Ligustrum Obtusifolium follow in that order.

• Journal of Biomedical Engineering Research
• /
• v.23 no.2
• /
• pp.81-85
• /
• 2002

In this paper, a new fragi1e watermarking algorithm for medical images is proposed. It makes possible to resolve the security and forgery problem of the medical images. In the proposed algorithm. the singularity which represents the inherent characteristic of the medical image is extracted and used as watermark. To extract the singularity point. we adopted Mallat wavelet transform because it can describe the edge of image exactly. Mallat wavelet transform produces horizontal and vertical subbands of the same resolution with the original image. The magnitude and phase components of the edge are obtained using these subbands. Based on the magnitude and phase components. LMM which will be used as watermark is determined. As LMM is the inherent singularity of image, if any forgery is applied to medical image, LMM of original and forged image are different each other Detecting the changes of LMM for the two images makes it possible whether any image is undergone forgery or not From the experimental results, we conformed that the proposed algorithm detects the forged area of the image very well.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2019.05a
• /
• pp.653-656
• /
• 2019

현대 사회에서의 생체인식 기술의 발전을 통해 홍채, 지분 등의 정보를 사용하여 사용자의 신원확인 등이 가능하게 되었으며, 생체정보의 유출/위조 방지에 대한 중요성이 높아지면서 관련 연구가 활발히 이루어 지고 있다. 본 논문에서는 홍체 전체의 이미지에 삽입하거나 동공의 중심에 가까운 DCT(Discrete Cosine Transform)영역에 삽입방법, 동공 중심과 눈매의 영역을 검출하여 거리 및 DC 계수를 통하여 삽입 위치를 선택하는 방법 등 홍채영상 속 워터마크를 삽입하여 유출/위조된 홍채 영상을 검출하는 방법에서의 워터마크 삽입위치에 관한 방법을 연구하고, CASIA Irisimage Database ver 4.0의 워터마크를 삽입하여 NC(Normalized Correlation)의 값을 비교하여 워터마크 삽입 실험을 검증하였다.