• Korean Journal of Remote Sensing
• /
• v.23 no.5
• /
• pp.409-420
• /
• 2007

Since 1988, pine wilt disease has spread over rapidly in Korea. It is not easy to detect the damaged pine trees by pine wilt disease from conventional remote sensing skills. Thus, many possibilities were investigated to detect the damaged pines using various kinds of remote sensing data including high spatial resolution satellite image of 2000/2003 IKONOS and 2005 QuickBird, aerial photos, and digital airborne data, too. Time series of B&W aerial photos at the scale of 1:6,000 were used to validate the results. A local maximum filtering was adapted to determine whether the damaged pines could be detected or not at the tree level from high resolution satellite images, and to locate the damaged trees. Several enhancement methods such as NDVI and image transformations were examined to find out the optimal detection method. Considering the mean crown radius of pine trees, local maximum filter with 3 pixels in radius was adapted to detect the damaged trees on IKONOS image. CIR images of 50 cm resolution were taken by PKNU-3(REDLAKE MS4000) sensor. The simulated CIR images with resolutions of 1 m, 2 m, and 4 m were generated to test the possibility of tree detection both in a stereo and a single mode. In conclusion, in order to detect the pine tree damaged by pine wilt disease at a tree level from satellite image, a spatial resolution might be less than 1 m in a single mode and/or 1 m in a stereo mode.

• Journal of Digital Convergence
• /
• v.17 no.8
• /
• pp.95-104
• /
• 2019

Recently, software education has been emphasized as a key element of the fourth industrial revolution. Many universities are strengthening the software education for all students according to the needs of the times. The use of online content is an effective way to introduce SW education for all students. However, the provision of uniform online contents has limitations in that it does not consider individual characteristics(major, sw interest, comprehension, interests, etc.) of students. In this study, we propose a recommendation method that utilizes the directional similarity between contents in the boolean view history data environment. We propose a new item-based recommendation formula that uses the confidence value of association rule analysis as the similarity level and apply it to the data of domestic paid contents site. Experimental results show that the recommendation accuracy is improved than when using the traditional collaborative recommendation using cosine or jaccard for similarity measurements.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2022.05a
• /
• pp.431-433
• /
• 2022

With the development of IoT technology, various technologies such as artificial intelligence and automation are being grafted into industrial sites, and accordingly, the importance of data processing is increasing. Image denoising is one of the basic processes of image processing, and is used as a preprocessing step in many applications. Various studies have been conducted to remove noise, but various problems arise in the process of noise removal, such as image detail preservation, texture restoration, and special noise removal. In this paper, we propose a digital filter using an extended convolutional mask to preserve image detail during the impulse denoising process. The proposed algorithm uses an extended convolution mask as a filtering mask, and obtains the final output by switching the extension level according to the noise level. Simulation was conducted to evaluate the performance of the proposed algorithm, and the performance was analyzed compared to the existing method.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2022.10a
• /
• pp.139-141
• /
• 2022

As interest in digital video media and intelligent systems increases rapidly, technologies using video information are being combined and used in various fields such as security and artificial intelligence. Impulse noise generated during digital image processing degrades the image quality of the image and reduces the reliability of information, so it is necessary to remove it through a filter. There are SMF, AWMF, and MDBUTMF as well-known antecedent methods, but they all have limitations in achieving seamless filtering in environments with large loss of information on valid pixels due to problems with the algorithm itself. Therefore, this paper designs a median filter algorithm that applies weights reflecting the reliability of the information by searching for the nearest effective pixels present within the mask. For performance evaluation, this algorithm and the preceding algorithm were compared and analyzed using PSNR and enlarged images.

• 전자공학회논문지 IE
• /
• v.47 no.4
• /
• pp.18-27
• /
• 2010

This paper is designed the efficient Data Acquisition System for an vibration of rotatory machines. The Data Acquisition System is consist of the analog logic having signal filer and amplifier, and digital logic with ADC, DSP, FPGA and FIFO memory. The vibration signal of rotatory machines acquired from sensors is controlled by the FPGA device through the analog logic and is saved to FIFO memory being converted analog to digital signal. The digital signal process is performed by the DSP using the vibration data in FIFO memory. The vibration factor of the rotatory machinery analysis and diagnosis is defined the RMS, Peak to Peak, average, GAP, FFT of vibration data and digital filtering by DSP, and is need to follow as being happened the event of vibration and make an application to an warning system. It takes time to process the several analysis step of all vibration data and the event follow, also special event. It should be continuously performed the data acquisition and the process, however during processing the input signal the DSP can not be performed to the acquisited data after then, also it will be lose the data at several channel. Therefore it is that the system uses efficiently the DSP and FPGA devices for reducing the data lose, it design to process a part of the signal data to FPGA from DSP in order to minimize the process time, and a process to parallel process system, as a result of design system it propose to method of faster process and more efficient data acquisition system by using DSP and FPGA than signal DSP system.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.14 no.3
• /
• pp.587-594
• /
• 2010

In this paper, we propose an asynchronous IR-UWB ranging system based on the two-way ranging protocol. The periodic pulse sequence is used to measure a distance between two devices. At the receiver, a received signal is first transformed into a frequency-domain signal using an analog correlator bank and digital signal processing is followed in the frequency-domain. This make it possible for the system to use an ADC with a conversion speed of pulse rate. The proposed algorithm at the receiver side includes a peak detection procedure using mutipath channel compensation and matched filtering, and retransmits a pulse sequence synchronized with the detected peak. The validity of the proposed algorithm is verified from simulation results where the CM1 channel is assumed.

• Journal of Electrical Engineering and Technology
• /
• v.7 no.4
• /
• pp.646-651
• /
• 2012

Meaningful logos or random sequences have been used in the current digital watermarking techniques of 2D bar code. The meaningful logos can not only be created by copyright holders based on their unique information, but are also very effective when representing their copyrights. The random sequences enhance the security of the watermark for verifying one's copyrights against intentional or unintentional attacks. In this paper, we propose a new watermarking technique taking advantage of Data Matrix as well as encryption keys. The Data Matrix not only recovers the original data by an error checking and correction algorithm, even when its high-density data storage and barcode are damaged, but also encrypts the copyright verification information by randomization of the barcode, including ownership keys. Furthermore, the encryption keys and the patterns are used to localize the watermark, and make the watermark robust against attacks, respectively. Through the comparison experiments of the copyright information extracted from the watermark, we can verify that the proposed method has good quality and is robust to various attacks, such as JPEG compression, filtering and resizing.

• The Research Journal of the Costume Culture
• /
• v.20 no.6
• /
• pp.869-882
• /
• 2012

The purpose of this study is to obtain the patent for extracting the color map and color chip from the color image source and to develop color image map for fashion design. For this study, fashion image maps were produced from 210 pictures with Adobe Photoshop CS2 program targeting 200 university students from 2004 to 2006. The procedures for extracting the color map and color chip included providing the color image, the filtering phase, the segmentation phase, the extraction phrase, and the arrangement phase. Based on the results of this study, patent application was made to KIPO(Korean Intellectual Property Office) for this invention. The following effects can be expected from the standpoint of design based on the case study. First, it is a straight forward procedure to extract a color chip and color map from a color image. Second, it can be applied to various art works based on the recombination of colors as representative colors can be extracted from the related color image that combines a variety of colors. Third, desired colors can be selected based on the taste cluster classification or sensibility axis of design by extracting the representative color from the color image.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.34 no.7C
• /
• pp.671-680
• /
• 2009

The diagnostic medical images(CT, MRI) in PACS require large storage and long transmission time. A simple and cheap way of overcoming these limitations is to increase the compression ratio. However, this requires a clinical validation for accurate diagnostic applications. The aim of this paper is to improve the compression efficiency of lossless JPEG2000 for diagnostic CT images by performing a visual-Iossless threshold filtering in high frequency subband. A proposed method, based on 5/3 reversible DWT, provides different subband-threshold values according to the compression ratio and gives the high subjective quality to reconstructed diagnostic CT images.

• Proceedings of the Korean Society of Broadcast Engineers Conference
• /
• 2008.11a
• /
• pp.149-152
• /
• 2008

본 논문에서는 디지털화된 형태로 취득 및 저장된 홀로그램 신호를 압축하는 새로운 알고리즘을 제안한다. 제안한 알고리즘은 취득한 디지털 홀로그램을 일정한 영역으로 분리하여 다수의 세그먼트로 만든다. 광학적인 특성상 각각의 세그먼트들은 각각의 공간적인 위치에서 객체를 촬영한 것과 같은 성분을 포함한다. 다음으로, 이 세그먼트들에 대해서 Fresnel 변환의 기저함수와 유사한 코사인 변환(Discrete Cosine Transform)을 적용하면 원 객체와 유사한 정보를 얻게 된다. 시각적으로 유사한 특성을 갖는, 즉 상관성을 갖는 세그먼트들을 하나의 비디오 스트림으로 구성하고 MCTF(Motion Compensated Temporal Filtering)을 적용한다. MCTF를 통해 얻어진 두 개의 스트림은 MCTF 과정 동안 움직임 보상 과정을 거치면서 재구성되므로 상당히 높은 압축 효율을 보일 수 있다. 마지막으로 이러한 과정을 통해 얻어진 두 개의 스트림은 각각 H.264를 통해 압축된다. 실험결과를 살펴보면 기존의 연구에 비해서 약 11%의 압축 효율이 증가한 것을 확인할 수 있었다. 따라서 제안한 기술은 디지털 홀로그램의 부호화를 위한 좋은 연구 사례가 될 것으로 사료된다.