• Title/Summary/Keyword: Vision area

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Adaptive V1-MT model for motion perception

  • Li, Shuai;Fan, Xiaoguang;Xu, Yuelei;Huang, Jinke
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.13 no.1
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    • pp.371-384
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    • 2019
  • Motion perception has been tremendously improved in neuroscience and computer vision. The baseline motion perception model is mediated by the dorsal visual pathway involving the cortex areas the primary visual cortex (V1) and the middle temporal (V5 or MT) visual area. However, few works have been done on the extension of neural models to improve the efficacy and robustness of motion perception of real sequences. To overcome shortcomings in situations, such as varying illumination and large displacement, an adaptive V1-MT motion perception (Ad-V1MTMP) algorithm enriched to deal with real sequences is proposed and analyzed. First, the total variation semi-norm model based on Gabor functions (TV-Gabor) for structure-texture decomposition is performed to manage the illumination and color changes. And then, we study the impact of image local context, which is processed in extra-striate visual areas II (V2), on spatial motion integration by MT neurons, and propose a V1-V2 method to extract the image contrast information at a given location. Furthermore, we take feedback inputs from V2 into account during the polling stage. To use the algorithm on natural scenes, finally, multi-scale approach has been used to handle the frequency range, and adaptive pyramidal decomposition and decomposed spatio-temporal filters have been used to diminish computational cost. Theoretical analysis and experimental results suggest the new Ad-V1MTMP algorithm which mimics human primary motion pathway has universal, effective and robust performance.

Post-yielding tension stiffening of reinforced concrete members using an image analysis method with a consideration of steel ratios

  • Lee, Jong-Han;Jung, Chi-Young;Woo, Tae-Ryeon;Cheung, Jin-Hwan
    • Advances in concrete construction
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    • v.7 no.2
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    • pp.117-126
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    • 2019
  • When designing reinforced concrete (RC) members, the rebar is assumed to resist all tensile forces, but the resistance of the concrete in the tension area is neglected. However, concrete can also resist tensile forces and increase the tensile stiffness of RC members, which is called the tension stiffening effect (TSE). Therefore, this study assessed the TSE, particularly after yielding of the steel bars and the effects of the steel ratio on the TSE. For this purpose, RC member specimens with steel ratios of 2.87%, 0.99%, and 0.59% were fabricated for uniaxial tensile tests. A vision-based non-contact measurement system was used to measure the behavior of the specimens. The cracks on the specimen at the stabilized cracking stage and the fracture stage were measured with the image analysis method. The results show that the number of cracks increases as the steel ratio increases. The reductions of the limit state and fracture strains were dependent on the ratio of the rebar. As the steel ratio decreased, the strain after yielding of the RC members significantly decreased. Therefore, the overall ductility of the RC member is reduced with decreasing steel ratio. The yielding plateau and ultimate load of the RC members obtained from the proposed equations showed very good agreement with those of the experiments. Finally, the image analysis method was possible to allow flexibility in expand the measurement points and targets to determine the strains and crack widths of the specimens.

Verification of Long-distance Vision-based Displacement Measurement System (장거리 영상기반 변위계측 시스템 검증)

  • Kim, Hong-Jin;Heo, Suk-Jae;Shin, Seung-Hoon
    • Journal of the Regional Association of Architectural Institute of Korea
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    • v.20 no.6
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    • pp.47-54
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    • 2018
  • The purpose of this study is to verify the long - range measurement performance for practical field application of VDMS. The reliability of the VDMS was verified by comparison with the existing monitoring sensor, GPS, Accelerometer and LDS. It showed the ability to accurately measure the dynamic displacement by tracking a motion of free vibration of target. And using the PSD function of measured data, the results in the frequency domain were also analyzed. We judged that VDMS is able to identify the higher system mode and has sufficient reliability. Based on the reliability verification, we conducted tests for long-distance applicability for actual application of VDMS. The distance from the stationary target model structure was increased by 50m interval, and the maximum distance was set to 400m. From the distance of 150m, the image obtained by the commercial camcorder has an error in the analysis, so the measured displacement comparison was performed between the LDS and the refractor telescope measurement results. In the measurement results of the displacement area of VDMS, the data validity was deteriorated due to the data shift by the external force and the quality degradation of the enlarged image. However, even under the condition that the effectiveness of the displacement measurement data of VDMS is low, the first mode characteristic included in the free vibration of the object is clearly measured. If the influence from the external environment is controlled and stable data is collected, It is judged that reliability of long-distance VDMS can be secured.

Robust Hand Region Extraction Using a Joint-based Model (관절 기반의 모델을 활용한 강인한 손 영역 추출)

  • Jang, Seok-Woo;Kim, Sul-Ho;Kim, Gye-Young
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.20 no.9
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    • pp.525-531
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    • 2019
  • Efforts to utilize human gestures to effectively implement a more natural and interactive interface between humans and computers have been ongoing in recent years. In this paper, we propose a new algorithm that accepts consecutive three-dimensional (3D) depth images, defines a hand model, and robustly extracts the human hand region based on six palm joints and 15 finger joints. Then, the 3D depth images are adaptively binarized to exclude non-interest areas, such as the background, and accurately extracts only the hand of the person, which is the area of interest. Experimental results show that the presented algorithm detects only the human hand region 2.4% more accurately than the existing method. The hand region extraction algorithm proposed in this paper is expected to be useful in various practical applications related to computer vision and image processing, such as gesture recognition, virtual reality implementation, 3D motion games, and sign recognition.

A Study on the Process Simulation Analysis of the High Precision Laser Scriber (고정밀 레이저 스크라이버 장비의 공정 시뮬레이션 분석에 관한 연구)

  • Choi, Hyun-Jin;Park, Kee-Jin
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.18 no.7
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    • pp.56-62
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    • 2019
  • The high-precision laser scriber carries out scribing alumina ceramic substrates for manufacturing ultra-small chip resistors. The ceramic substrates are loaded, aligned, scribed, transferred, and unloaded. The entire process is fully automated, thereby minimizing the scribing cycle time of the ceramic substrates and improving the throughput. The scriber consists of the laser optical system, pick-up module of ceramic substrates, pre-alignment module, TH axis drive work table, automation module for substrate loading / unloading, and high-speed scribing control S/W. The loader / unloader unit, which has the greatest influence on the scribing cycle time of the substrates, carries the substrates to the work table that carries out the cutting line work by driving the X and Y axes as well as by adsorbing the ceramic substrates. The loader / unloader unit consists of the magazine up / down part, X-axis drive part for conveying the substrates to the left and right direction, and the vision part for detecting the edge of the substrate for the primary pre-alignment of the substrates. In this paper, the laser scribing machining simulation is performed by applying the instrument mechanism of each component module. Through this study, the scribing machining process is first verified by analyzing the process operation and work area of each module in advance. In addition, the scribing machining process is optimized by comparing and analyzing the scribing cycle time of one ceramic substrate according to the alignment stage module speed.

A Conjunction of Folklife and Archival Science : New Dimension for Folklife Archival Science (민속과 기록의 만남, '민속기록학'을 제창한다)

  • Kim, Duk-Muk
    • The Korean Journal of Archival Studies
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    • no.34
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    • pp.165-219
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    • 2012
  • Folklife archival science(folklife: Folklore is generally used in Engish-speaking countries but it has a strong meaning as remnants of former times. That's why I am useing the term-folklife instead of folklore in this paper. I think folklife is more appropriate term for expressing studies on daily life culture and also my intention to unite the both word in this paper) is a new academic movement, I propose, which is intended on convergence of advantage of folklife and archival science. In other words, taking advantage of the two branches of study(folklife, archival science), it becomes a practical studies which systematically organize records, preservations and application on living culture in any community. It demonstrate deeply on archiving and archive and It conducts a probe into records, preservations and applications. It is a method of technical study in order to record communities like village, rural society and modern city. In the mean time, there is no well defined and established methodology for archival science and for folk-area or community archiving. And therefore, It needs a research methodology in a folklife. In the other hand, there is a lack of a theoretical basis, methodological strategy and clear vision over folklife and field survey or method of survey. Therefore, converging advatage of the two studies(folklife, archival science), we can combine professionalism of community archiving and methodological strategy together.

Bridge Inspection and condition assessment using Unmanned Aerial Vehicles (UAVs): Major challenges and solutions from a practical perspective

  • Jung, Hyung-Jo;Lee, Jin-Hwan;Yoon, Sungsik;Kim, In-Ho
    • Smart Structures and Systems
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    • v.24 no.5
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    • pp.669-681
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    • 2019
  • Bridge collapses may deliver a huge impact on our society in a very negative way. Out of many reasons why bridges collapse, poor maintenance is becoming a main contributing factor to many recent collapses. Furthermore, the aging of bridges is able to make the situation much worse. In order to prevent this unwanted event, it is indispensable to conduct continuous bridge monitoring and timely maintenance. Visual inspection is the most widely used method, but it is heavily dependent on the experience of the inspectors. It is also time-consuming, labor-intensive, costly, disruptive, and even unsafe for the inspectors. In order to address its limitations, in recent years increasing interests have been paid to the use of unmanned aerial vehicles (UAVs), which is expected to make the inspection process safer, faster and more cost-effective. In addition, it can cover the area where it is too hard to reach by inspectors. However, this strategy is still in a primitive stage because there are many things to be addressed for real implementation. In this paper, a typical procedure of bridge inspection using UAVs consisting of three phases (i.e., pre-inspection, inspection, and post-inspection phases) and the detailed tasks by phase are described. Also, three major challenges, which are related to a UAV's flight, image data acquisition, and damage identification, respectively, are identified from a practical perspective (e.g., localization of a UAV under the bridge, high-quality image capture, etc.) and their possible solutions are discussed by examining recently developed or currently developing techniques such as the graph-based localization algorithm, and the image quality assessment and enhancement strategy. In particular, deep learning based algorithms such as R-CNN and Mask R-CNN for classifying, localizing and quantifying several damage types (e.g., cracks, corrosion, spalling, efflorescence, etc.) in an automatic manner are discussed. This strategy is based on a huge amount of image data obtained from unmanned inspection equipment consisting of the UAV and imaging devices (vision and IR cameras).

Annual Changes of Soil Salinity of the Saemangeum Reclaimed Tide Land during Last 10 Years (새만금 간척지 토양 염농도의 경시적 변동 특성: 10년 조사 결과)

  • Ryu, Jin-Hee;Oh, Yang-Yeol;Lee, Su-Hwan;Lee, Kyung-Do;Kim, Young-Joo
    • Korean Journal of Environmental Agriculture
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    • v.39 no.4
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    • pp.327-333
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    • 2020
  • BACKGROUND: Through Saemangeum development project, 283 ㎢ of new land is planned to be created and the reclaimed land of 89.7 ㎢ will be used as agricultural land. Therefore, monitoring of soil salinity is required to evaluate the suitability of the land for agricultural purposes. METHODS AND RESULTS: We investigated changes of soil physico-chemical properties, including electric conductivity (EC), of the Saemangeum reclaimed tidal land (1,195 ha) from 2008 to 2017 to obtain basic data for suitable soil management of the Saemangeum reclaimed tidal land. Soil samples were collected from the sites spaced 200 meters apart from each other. Soil analysis results showed that average soil EC was 14.5 dS m-1 in 2008, and decreased to 6.5 dS m-1 in 2014 and to 0.9 dS m-1 in 2017. Accordingly, the soil area below soil EC 4.7 dS m-1 (accepted as farmable soil salinity) increased; 25.0% in 2008, 54.3% in 2014, and 96.9% in 2017. The annual decrease in soil EC was described as y = -1.5756x + 14.6 (R2= 0.96), where y = soil EC and x = elapsed years since 2008. CONCLUSION: The soil salinity have decreased to a level for cultivation of most edible crops. However, since the soil chemical properties, such as soil organic matter were inadequate for the cultivation of crops, it was suggested that management of soil fertility would be important for efficient agricultural use of Saemangeum reclaimed land.

Real Time Hornet Classification System Based on Deep Learning (딥러닝을 이용한 실시간 말벌 분류 시스템)

  • Jeong, Yunju;Lee, Yeung-Hak;Ansari, Israfil;Lee, Cheol-Hee
    • Journal of IKEEE
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    • v.24 no.4
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    • pp.1141-1147
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    • 2020
  • The hornet species are so similar in shape that they are difficult for non-experts to classify, and because the size of the objects is small and move fast, it is more difficult to detect and classify the species in real time. In this paper, we developed a system that classifies hornets species in real time based on a deep learning algorithm using a boundary box. In order to minimize the background area included in the bounding box when labeling the training image, we propose a method of selecting only the head and body of the hornet. It also experimentally compares existing boundary box-based object recognition algorithms to find the best algorithms that can detect wasps in real time and classify their species. As a result of the experiment, when the mish function was applied as the activation function of the convolution layer and the hornet images were tested using the YOLOv4 model with the Spatial Attention Module (SAM) applied before the object detection block, the average precision was 97.89% and the average recall was 98.69%.

The Analysis on Trend of Articles about Strabismus in Journal of Korean Medicine (국내 한의학 학술지에 게재된 사시 관련 논문들의 경향성 분석)

  • Kim, Young-Bin;Kwon, Kang
    • The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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    • v.34 no.1
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    • pp.13-28
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    • 2021
  • Objectives : Strabismus is a disease that can be observed and treated directly from the outside. Therefore, it is very important in Korean medicine ophthalmology in accessibility to treatment. This study is designed to investigate the trends of strabismus-related studies published in Journal of Korean medicine. Methods : 5 Internet databases were selected to search for the study subject. The following 9 keywords were used; Strabismus, Heterophoria, Binocular vision, Visual acuity, Diplopia, Paralytic, Cover test, Oculomotor nerve paralysis, Abducens nerve paralysis. Through this process, a total of 45 studies were found and analyzed into 5 categories ; publication year, publication journal, number of author, type of article, analyzation of case report. Results : There were 2 review articles, 1 original article and 42 case reports. 5 studies(11.1%) were published in 2004 year. Journal of Korean Oriental Medical Ophthalmology & Otolaryngology & Dermatology were the most common with 40%. The authors were often 2 and 3 (each 22.2%). In the case report study, the treatment period was most often 1-30 days (35.7%). Conclusions : 42 studies were on paralytic strabismus and 1 study was on paralytic and non-paralytic strabismus. These results represent that the studies are concentrated in case reports about paralytic strabismus, but this seems to be an area to be improved in future research.