• Journal of Information Processing Systems
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• 제10권2호
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• pp.283-299
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• 2014

Skin detection is used in many applications, such as face recognition, hand tracking, and human-computer interaction. There are many skin color detection algorithms that are used to extract human skin color regions that are based on the thresholding technique since it is simple and fast for computation. The efficiency of each color space depends on its robustness to the change in lighting and the ability to distinguish skin color pixels in images that have a complex background. For more accurate skin detection, we are proposing a new threshold based on RGB and YUV color spaces. The proposed approach starts by converting the RGB color space to the YUV color model. Then it separates the Y channel, which represents the intensity of the color model from the U and V channels to eliminate the effects of luminance. After that the threshold values are selected based on the testing of the boundary of skin colors with the help of the color histogram. Finally, the threshold was applied to the input image to extract skin parts. The detected skin regions were quantitatively compared to the actual skin parts in the input images to measure the accuracy and to compare the results of our threshold to the results of other's thresholds to prove the efficiency of our approach. The results of the experiment show that the proposed threshold is more robust in terms of dealing with the complex background and light conditions than others.

• 한국지능시스템학회논문지
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• 제16권6호
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• pp.698-703
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• 2006

본 논문에서는 비전 시스템과 후각 센서를 이용하여 자율주행 이동로봇에 냄새 발생지 추적을 위한 기능을 구현하였다. 초기에 로봇에 부착된 후각 센서가 냄새를 탐지하지 못한 경우에는 비전 시스템을 이용하여 특정 지역 내를 운행을 하다가 시계 내의 한 물체에 접근하여 냄새를 방출하고 있는 지를 검사하게 된다. 만일 냄새를 방출하고 있다면 신경회로망을 이용한 냄새 구별 알고리즘을 이용하여 그 냄새가 찾고자 하는 것인지를 확인하게 된다. 실험을 위해 AMOR(Autonomous Mobile Olfactory Robot) 로봇을 구현하여 사용하였으며, 실험결과는 제안된 알고리즘이 냄새 발생지를 찾고 냄새를 구별해 내는데 효율성이 있음을 보여준다.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2015년도 학술발표회
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• pp.79-79
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• 2015

현재 홍수 시 유량조사에 가장 많이 사용하고 있는 부자법은 측정 인력, 측정비용 및 위험성이 높다는 단점이 있다. 또한 교량에서 부자를 투하하고 측면에서 부자의 이동을 추적하기 때문에 평면상의 이동에 대한 정보를 얻기 어렵다는 한계가 있다. 이에 김서준 등(2014)은 PTV 기법을 이용한 부자 추적 알고리즘을 개발하였으나 부자가 회전하거나 물속에 잠기는 부분이 변화하여 수면 위로 확인되는 부자의 길이가 변할 경우 추적이 어렵다는 한계가 있었다. 이를 개선하고자 본 연구에서는 Template Match 알고리즘과 색상 기반 영상 처리 기법을 이용한 목표물 인식 방법인 Camshift 기법을 적용하여 부자를 추적할 수 있는 알고리즘을 개발하였다. Template Match 알고리즘의 경우는 입자가 많을수록 추적을 잘한다는 장점이 있지만 회전 및 변형에 취약하다는 단점이 있고, Camshift 영상 처리 기법의 경우 다수의 추적자가 존재할 경우 추적에 어려움이 있으나 추적자의 회전과 변형을 정확하게 추적할 수 있다는 장점이 있다. 따라서 Template Match 알고리즘을 이용하여 이동 예상영역을 결정하고 Camshift 영상 처리 기법으로 추적을 하게되면 두 방법의 장점을 모두 살릴 수 있다. Camshift 영상 처리 기법을 실제 부자 추적에 적용해 본 결과 부자의 회전 및 변형에도 정확하게 추적할 수 있는 것을 확인하였다. 향후 부자법을 이용한 유량 조사에 본 연구에서 개발한 알고리즘을 적용한다면 현장에서 동영상 촬영만 하면 되기 때문에 측정 인원을 최소화 할 수 있어 매우 경제적이고, 홍수 시 위험성도 감소할 것으로 기대된다.

• 한국멀티미디어학회논문지
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• 제22권2호
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• pp.136-145
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• 2019

The crowded environment of a domestic pig farm is highly vulnerable to the spread of infectious diseases such as foot-and-mouth disease, and studies have been conducted to automatically analyze behavior of pigs in a crowded pig farm through a video surveillance system using a camera. Although it is required to correctly separate occluding pigs for tracking each individual pigs, extracting the boundaries of the occluding pigs fast and accurately is a challenging issue due to the complicated occlusion patterns such as X shape and T shape. In this study, we propose a fast and accurate method to separate occluding pigs not only by exploiting the characteristics (i.e., one of the fast deep learning-based object detectors) of You Only Look Once, YOLO, but also by overcoming the limitation (i.e., the bounding box-based object detector) of YOLO with the test-time data augmentation of rotation. Experimental results with two-pigs occlusion patterns show that the proposed method can provide better accuracy and processing speed than one of the state-of-the-art widely used deep learning-based segmentation techniques such as Mask R-CNN (i.e., the performance improvement over Mask R-CNN was about 11 times, in terms of the accuracy/processing speed performance metrics).

• Journal of Multimedia Information System
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• 제6권1호
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• pp.23-30
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• 2019

A communications profile is a system that acquires information from communication links to an ambulance or other vehicle moving on a road and compiles a database based on this information. The equipment (six sets of HDTVs, fish-eye camera, satellite antenna with tracking system, and receiving power from the satellite beacon of the N-star) mounted on the roof of the vehicle, image data were obtained at Yokohama Japan. From these data, the polygon of the building was actually produced and has arranged on the map of the Geographical Survey Institute of a 50 m-mesh. The optical study (relationship between visibility rate and elevation angle) were performed on actual data taken by fish-eye lens, and simulated data by 3D-Map with polygons. There was no big difference. This 3D map system then predicts the communication links that will be available at a given location. For line-of-sight communication, optical analysis allows approximation if the frequency is sufficiently high. For non-line-of-sight communication, previously obtained electric power data can be used as reference information for approximation in certain cases when combined with predicted values calculated based on a 3D map. 3D maps are more effective than 2D maps for landing emergency medical helicopters on public roadways in the event of a disaster. Using advanced imaging technologies, we have produced a semi-automatic creation of a high-precision 3D map at Yokohama Yamashita Park and vicinity and assessed its effectiveness on telecommunications and ambulatory merits.

• 산경연구논집
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• 제13권6호
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• pp.1-7
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• 2022

Purpose: This study aims to investigate an overview of the reputation of e-commerce from 2001-2021. Research design, data and methodology: This study uses a bibliometrics technique involving published results from the Scopus database. Keyword tracking uses the terms e-commerce + reputation. The data collected meets the criteria for the type of journal publication. Data was collected using the Publish or Perish (PoP) program and exported into VOSviewer. Bibliometrics examines certain fields of science based on several components such as author and co-author, citation and co-citation, keywords related to theme mapping, origin, and source of publication. Data was collected using the Publish or Perish (PoP) program and exported into VOSviewer. Results: The results show the total citations from 118 papers are 1429, with citations per paper of 12.11 and citations per year of 68.05. The trend of publications from 2001-2021 shows the dynamics of increasing or decreasing, but this trend is still developing. Conclusions: This paper also presents articles that have contributed greatly to the study of e-commerce reputation, the most productive authors, and clustered themes regarding e-commerce reputation. Reputation is an important area of e-commerce research. Reputation is also essential factors for e-commerce in facing business competition and needs to be a consideration for digital business practitioners.

• Nuclear Engineering and Technology
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• 제53권1호
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• pp.79-92
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• 2021

Venturi tube is based on turbulent flow, whereby the microbubbles can be generated by the turbulent fragmentation. This phenomenon is common in several venturi bubblers used by the nuclear, aerospace and chemical industries. The first objective of this paper is to study the liquid-phase velocity field experimentally and develop correlations for the turbulent quantities. The second objective is to research velocity field characteristics theoretically. Stereoscopic PIV measurements for the velocity field have been analyzed and utilized to develop the turbulent kinetic energy in the venturi tube. The tracking properties of the tracer particles have been verified enough for us to analyze the turbulence field. The turbulence kinetic energy has a bimodal distribution trend. Also, the results of turbulence intensity along the horizontal direction is gradually uniform along the downstream. Both the mean velocity and the fluctuation velocity are proportional to the Reynolds number. Besides, the distribution trend of the mean velocity and the velocity fluctuation can be determined by the geometric parameters of the venturi tube. An analytical function model for the flow field has been developed to obtain the approximate analytical solutions. Good agreement is observed between the model predictions and experimental data.

• International journal of advanced smart convergence
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• 제11권2호
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• pp.7-12
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• 2022

Safety and security are the topmost priority in every environment. With the aid of Artificial Intelligence (AI), many objects are becoming more intelligent, conscious, and curious of their surroundings. The recent scientific breakthroughs in autonomous vehicular designs and development; powered by AI, network of sensors and the rapid increase of Internet of Things (IoTs) could be utilized in maintaining safety and security in our environments. AI based on deep learning architectures and models, such as Deep Neural Networks (DNNs), is being applied worldwide in the automotive design fields like computer vision, natural language processing, sensor fusion, object recognition and autonomous driving projects. These features are well known for their identification, detective and tracking abilities. With the embedment of sensors, cameras, GPS, RADAR, LIDAR, and on-board computers in many of these autonomous vehicles being developed, these vehicles can properly map their positions and proximity to everything around them. In this paper, we explored in detail several ways in which these enormous features embedded in these autonomous vehicles, such as the network of sensors fusion, computer vision and natural image processing, natural language processing, and activity aware capabilities of these automobiles, could be tapped and utilized in safeguarding our lives and environment.

• 로봇학회논문지
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• 제17권1호
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• pp.8-15
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• 2022

In this paper, we proposed the method of virtual reality-based surgical navigation to reproduce the pre-planned position and angle of the pedicle screw in spinal fusion surgery. The goal of the proposed method is to quantitatively save the surgical plan by applying a virtual guide coordinate system and reproduce it in the surgical process through virtual reality. In the surgical planning step, the insertion position and angle of the pedicle screw are planned and stored based on the virtual guide coordinate system. To implement the virtual reality-based surgical navigation, a vision tracking system is applied to set the patient coordinate system and paired point-based patient-to-image registration is performed. In the surgical navigation step, the surgical plan is reproduced by quantitatively visualizing the pre-planned insertion position and angle of the pedicle screw using a virtual guide coordinate system. We conducted phantom experiment to verify the error between the surgical plan and the surgical navigation, the experimental result showed that target registration error was average 1.47 ± 0.64 mm when using the proposed method. We believe that our method can be used to accurately reproduce a pre-established surgical plan in spinal fusion surgery.

• Current Optics and Photonics
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• 제6권1호
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• pp.79-85
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• 2022

Tracers are one of the critical factors for improving the performance of velocimetry. Silver and gold nanoparticles as tracers with localized surface-plasmon resonance are analyzed for their scattering properties. The scattering cross sections, angular distribution of the scattering, and equivalent scattering cross sections from 53° and 1.5° half-angle cones at 532 nm are calculated, with particle sizes in the nanoscale range. The 53° and 1.5° half-angle cones used as examples correspond respectively to the collection cones for microscope objectives in microscopic measurements and camera lenses in macroscopic measurements. We find that there is a transitional size near 35 nm when comparing the equivalent scattering cross sections between silver and gold nanoparticles in water at 532 nm. The equivalent scattering cross section of silver nanoparticles is greater or smaller than that of gold nanoparticles when the particle radius is greater or smaller than 35 nm respectively. When the radius of the plasmonic nanoparticles is smaller than about 44 nm, their equivalent scattering cross sections are at least ten times that of TiO₂ nanoparticles. Plasmonic nanoparticles are promising for velocimetry applications.