• Journal of the Korea Society of Computer and Information
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• v.25 no.12
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• pp.127-134
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• 2020

Recently, Harmful sites, including pornographic videos, drugs, personal information and hacking tool distribution sites, have caused serious social problems. However, due to the nature of the Internet environment where anyone can use it freely, it is difficult to control the user effectively. And the site operator operates by changing the domain to bypass the blockage. Therefore, even once identified sites have low persistence. In this paper, we propose multi-channel domain tracking technology, a technique that can effectively track changes in the domain addresses of harmful sites, including the same or similar content, by tracking changes in these harmful sites. Proposed technology is a technology that can continuously track information in a domain using OSINT technology. We tested and verified that the proposed technology was effective for domain tracking with a 90.4% trace rate (sensing 66 changes out of 73 domains).

• Journal of the Korean Society of Radiology
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• v.82 no.3
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• pp.693-699
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• 2021

The inferior mesenteric artery is a rare source of postpartum hemorrhage. We report two cases of primary postpartum hemorrhage that originated from the inferior mesenteric artery after vaginal delivery. Both patients showed signs of hypovolemic shock, and disseminated intravascular coagulation was suspected. The bleeding continued even after embolization of the uterine artery, a typical source of postpartum hemorrhage. Inferior mesenteric arteriography confirmed contrast extravasation from the superior rectal artery, and selective embolization was performed using N-butyl cyanoacrylate. This report highlights that the inferior mesenteric artery can be a source of bleeding in patients with intractable and persistent postpartum hemorrhage due to birth canal injury.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.39 no.4
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• pp.211-221
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• 2021

The Rabbit grass(Trifolium Repens, call it 'Clover') is a representative harmful plant of lawn, and it starts growing earlier than lawn, forming a water pipe on top of the lawn and hindering the photosynthesis and growth of the lawn. As a result, in competition between lawn and clover, clover territory spreads, but lawn is damaged and dried up. Damage to the affected lawn area will accelerate during the rainy season as well as during the plant's rear stage, spreading the area where soil is exposed. Therefore, the restoration of damaged lawn is causing psychological stress and a lot of economic burden. The purpose of this study is to distinguish clover which is a representative harmful plant on lawn, to identify the distribution of damaged areas due to the spread of clover, and to review of changes in vegetation before and after the eradication of clover. For this purpose, a time series analysis of three vegetation indices calculated based on images of convergence Drone with RGB(Red Green Blue) and BG-NIR(Near Infra Red)sensors was reviewed to identify the separation between lawn and clover for selective eradication, and the distribution of damaged lawn for recovery plan. In particular, examined timeseries changes in the ecology of clover before and after the weed-whacking by manual and brush cutter. And also, the method of distinguishing lawn from clover was explored during the mid-year period of growth of the two plants. This study shows that the time series analysis of the MGRVI(Modified Green-Red Vegetation Index), NDVI(Normalized Difference Vegetation Index), and MSAVI(Modified Soil Adjusted Vegetation Index) indices of drone-based RGB and BG-NIR images according to the growth characteristics between lawn and clover can confirm the availability of change trends after lawn damage and clover eradication.

• Analytical Science and Technology
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• v.30 no.6
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• pp.390-404
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• 2017

• The Journal of the Acoustical Society of Korea
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• v.28 no.2
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• pp.141-147
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• 2009

This paper presents a new fast algorithm, rotation-based method (RBM), for the reconstruction of 3 dimensional image for cone beam computerized tomography (CB CT) system. The system used cone beam has less exposure time of radioactivity than fan beam. The Three-Pass Shear Matrices (TPSM) is applied, that has less transcendental functions than the one-pass shear method to decrease a time of calculations in the computer. To evaluate the quality of the 3-D images and the time for the reconstruction of the 3-D images, another 3-D images were reconstructed by the radon transform under the same condition. For the quality of the 3-D images, the images by radon transform was shown little good quality than REM. But for the time for the reconstruction of the 3-D images REM algorithm was 35 times faster than radon transform. This algorithm offered $4{\sim}5$ frames a second. It meant that it will be possible to reconstruct the 3-D dynamic images in real time.

• Journal of Internet Computing and Services
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• v.7 no.3
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• pp.107-118
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• 2006

Recently, network infra grows rapidly and the digital image compression technique have made remarkable progress, and therefore the demand of the real-time image surveillance system which uses a network camera server is increasing. Network Camera Server has emerged as an attractive alternative to the CCTV for the real-time image surveillance. From this reason, the demand regarding the development of the real-time image surveillance system which uses a network camera server is increasing as well. In this paper, we will provide a model for JPEG Streamer which is used in real-time image surveillance system. And we will design and implement this model. For the stability and efficiency of the JPEG Streamer, we'll use the thread pool and shared memory. We will also introduce the concept of double buffering for increasing the quality of real-time image, Using the JPEG Streamer, a raising of the productivity, reliability and stability will be able to secure to development of real-time image surveillance system.

• The Journal of the Acoustical Society of Korea
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• v.28 no.4
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• pp.370-374
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• 2009

In this paper, we presents a new cone beam computerized tomography (CB CT) system for the reconstruction of 3 dimensional dynamic images. The system using cone beam has less the exposure of radioactivity than fan beam, relatively. In the system, the reconstruction 3-D image is reconstructed with the radiation angle of X-ray in the image processing unit and transmitted to the monitor. And in the image processing unit, the Three Pass Shear Matrices, a kind of Rotation-based method, is applied to reconstruct 3D image because it has less transcendental functions than the one-pass shear matrix to decrease a time of calculations for the reconstruction 3-D image in the processor. The new system is able to get 3~5 3-D images a second, reconstruct the 3-D dynamic images in real time.

• Science of Emotion and Sensibility
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• v.24 no.2
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• pp.39-48
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• 2021

According to International Associating for the Study of Pain (IASP) definition, neuropathic pain is a disorder characterized by dysfunction of the nervous system that, under normal conditions, mediates virulent information to the central nervous system (CNS). This pain can be divided into a disease with provable lesions in the peripheral or central nervous system and states with an incorporeal lesion of any nerves. Both conditions undergo long-term and chronic processes of change, which can eventually develop into chronic pain syndrome, that is, nervous system is inappropriately adapted and difficult to heal. However, the treatment of neuropathic pain itself is incurable from diagnosis to treatment process, and there is still a lack of notable solutions. Recently, several studies have observed the responses of CNS to harmful stimuli using image analysis technologies, such as functional magnetic resonance imaging (fMRI), positron emission tomography (PET), and optical imaging. These techniques have confirmed that the change in synaptic-plasticity was generated in brain regions which perceive and handle pain information. Furthermore, these techniques helped in understanding the interaction of learning mechanisms and chronic pain, including neuropathic pain. The study aims to describe recent findings that revealed the mechanisms of pathological pain and the structural and functional changes in the brain. Reflecting on the definition of chronic pain and inspecting the latest reports will help develop approaches to alleviate pain.

• Electronics and Telecommunications Trends
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• v.26 no.3
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• pp.71-87
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• 2011

2004년 MIT 10대 신기술, 2005년 일본 총무성 10대 기간 기술로 선정된 테라헤르츠 기술 개발에 집중적인 연구개발이 진행되고 있다. 물질의 투과, 낮은 광자에너지로 식품, 인체에 상대적으로 안전하여 인간에 필요한 테라헤르츠 영상이나 인간에 유해한 물질을 추출하기 위한 테라헤르츠 분광기술에 관한 많은 가능성들을 제시하여 왔다. 또한, 영상 및 분광 이외에도 유무선 경계가 희박해지고 있는 시점에서 유무선 통합 기능제공이 가능하고 정보전달, 센싱, 비파괴 검사 등 다양한 응용영역으로 기술수요가 급격히 증가하고 있는 실정이다. 수요기술의 핵심은 언제, 어디서나, 실시간, 무고통으로 값싸게 활용하여 풍요롭고 안전한 삶을 유지하는 것으로 고령화 사회의 핵심 인프라 구축과 연동되어 가치를 공유하고 있다. 전자기파 대역에서의 초소형, 고효율, 실시간, 저가격 파원 및 검출기 기술개발의 장점을 갖는 포토닉스 기반 테라헤르츠 기술 동향에 대해 기술하였다.

• Journal of Biomedical Engineering Research
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• v.19 no.2
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• pp.113-118
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• 1998

By their rapid and periodic actions, the cilia of the human respiratory tract play an important role in clearing inhaled noxious particles. Based on the automated image-processing technique, we studied the method analyzing ciliary beat frequency (CBF) objectively and quantitatively. Microscopic ciliary images were transformed into digitized gray ones through an image-grabber, and from these we extracted signals for CBF. By means of a FFT, maximum peak frequencies were detected as CBFs in each partitioned block for the entire digitized field. With these CBFs, we composed distribution maps visually showing the spatial distribution of CBFs. Through distribution maps of CBF, the whole aspects of CBF changes for cells and the difference of CBF of neighboring cells can be easily measured and detected. Histogram statistics calculated from the user-defined polygonal window can show the local dominant frequency presumed to be the CBF of a cell or a crust the region includes.