• Title/Summary/Keyword: Camera Performance

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A Kinematic Characteristics of Throwing Performance on Period When Blind's became Sightless (시각장애인의 실명시기에 따른 던지기 동작의 운동학적 특성)

  • Choi, Jung-Kyu
    • Korean Journal of Applied Biomechanics
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    • v.18 no.2
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    • pp.125-139
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    • 2008
  • The purpose of this study is to compare and analyze a kinematic characteristics of throwing performance among born visually impaired, postnatal visually impaired and visually correct people through their kinematic characteristics. Another purpose of this study is to prevent injury and improve blind's exercise leadership and physical abilities. Three video cameras were used and each camera's shooting velocity was 60field/sec. Then the longest thrown pose was collected and analyzed by using Kwon 3D ver. 3.1 program. The results obtained from this study were followings; 1. During release, the fastest speed of ball was visually corrected followed by postnatal visually impaired and then born visually impaired. 2. Visually corrected used wrist joint well and had wide body round range with similar motion patterns, however born visually impaired couldn't do this at all. 3. Visually corrected used waist to lead shoulder at Phase 2 while throwing ball, but some of born visually impaired and postnatal visually impaired couldn't use waist to lead shoulder. 4. Visually corrected looked at the way where ball would go, but blinds couldn't look where ball would go. 5. Not like visually corrected who show similar patterns, born visually impaired showed each different patterns and some postnatal visually impaired showed similar patterns with visually corrected. 6. While throwing ball, visually corrected showed flexible weight-movement, postnatal visually impaired were not good as visually corrected, and born visually impaired couldn't do weight-movement at all. Synthetically, this result showed that throwing motions are affected a lot by the time when people became blind.

Development of the IRIS Collimator for the Portable Radiation Detector and Its Performance Evaluation Using the MCNP Code (IRIS형 방사선검출기 콜리메이터 제작 및 MCNP 코드를 이용한 성능평가)

  • Ji, Young-Yong;Chung, Kun Ho;Lee, Wanno;Choi, Sang-Do;Kim, Change-Jong;Kang, Mun Ja;Park, Sang Tae
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.13 no.1
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    • pp.55-61
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    • 2015
  • When a radiation detector is applied to the measurement of the radioactivity of high-level of radioactive materials or the rapid response to the nuclear accident, several collimators with the different inner radii should be prepared according to the level of dose rate. This makes the in-situ measurement impractical, because of the heavy weight of the collimator. In this study, an IRIS collimator was developed so as to have a function of controlling the inner radius, with the same method used in optical camera, to vary the attenuation ratio of radiation. The shutter was made to have the double tungsten layers with different phase angles to prevent the radiation from penetrating owing to the mechanical tolerance. The performance evaluation through the MCNP code was conducted by calculating the attenuation ratio according to the inner radius of the collimator. The attenuation ratio was marked on the outer scale ring of the collimator. It is expected that when a radiation detector with the IRIS collimator is used for the in-situ measurement, it can change the attenuation ratio of the incident photon to the detector without replacing the collimator.

A Study on Color Difference Discrimination for PVC Deco-Film using Entry-Level Digital Device (보급형 디지털 장비를 이용한 Deco-Film용 PVC의 색차판별에 대한 연구)

  • Im, Hoyoun;Kim, Minsoo
    • The Journal of Society for e-Business Studies
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    • v.22 no.1
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    • pp.1-13
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    • 2017
  • Though digital imaging devices such as smart phones, digital cameras and office scanners have improved significantly over the past years, they are seldom used for industrial application. This may be attributable to high level of quality and performance requirement for industrial application, but there lacks a test or an objective evaluation whether the upgraded performance of entry-level device is sufficiently enough to replace existing industrial equipments or not. If there exists an industrial application area where the applicability of entry-level equipment is proved by some objective tests, then companies will be able to reduce investment on expensive industrial equipment. In this study, applicability of entry-level digital devices for color difference discrimination of PVC (Polyvinyl chloride) color sheet is tested. By testing smart phone, digital camera, and office scanner for color difference discrimination, authors have found that office scanner shows consistent result with less measurement error. Additional experiment on comparing office scanner with industrial spectrophotometer has confirmed that there exists high correlation between the two devices' results. Based on this result, office scanner may be applicable to discriminate the color difference of PVC sheet instead of expensive industrial spectrophotometer if proper management criteria are established.

No-Reference Visibility Prediction Model of Foggy Images Using Perceptual Fog-Aware Statistical Features (시지각적 통계 특성을 활용한 안개 영상의 가시성 예측 모델)

  • Choi, Lark Kwon;You, Jaehee;Bovik, Alan C.
    • Journal of the Institute of Electronics and Information Engineers
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    • v.51 no.4
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    • pp.131-143
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    • 2014
  • We propose a no-reference perceptual fog density and visibility prediction model in a single foggy scene based on natural scene statistics (NSS) and perceptual "fog aware" statistical features. Unlike previous studies, the proposed model predicts fog density without multiple foggy images, without salient objects in a scene including lane markings or traffic signs, without supplementary geographical information using an onboard camera, and without training on human-rated judgments. The proposed fog density and visibility predictor makes use of only measurable deviations from statistical regularities observed in natural foggy and fog-free images. Perceptual "fog aware" statistical features are derived from a corpus of natural foggy and fog-free images by using a spatial NSS model and observed fog characteristics including low contrast, faint color, and shifted luminance. The proposed model not only predicts perceptual fog density for the entire image but also provides local fog density for each patch size. To evaluate the performance of the proposed model against human judgments regarding fog visibility, we executed a human subjective study using a variety of 100 foggy images. Results show that the predicted fog density of the model correlates well with human judgments. The proposed model is a new fog density assessment work based on human visual perceptions. We hope that the proposed model will provide fertile ground for future research not only to enhance the visibility of foggy scenes but also to accurately evaluate the performance of defog algorithms.

Hybrid (refrctive/diffractive) lens design for the ultra-compact camera module (초소형 영상 전송 모듈용 DOE(Diffractive optical element)렌즈의 설계 및 평가)

  • Lee, Hwan-Seon;Rim, Cheon-Seog;Jo, jae-Heung;Chang, Soo;Lim, Hyun-Kyu
    • Korean Journal of Optics and Photonics
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    • v.12 no.3
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    • pp.240-249
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    • 2001
  • A high speed ultra-compact lens with a diffractive optical element (DOE) is designed, which can be applied to mobile communication devices such as IMT2000, PDA, notebook computer, etc. The designed hybrid lens has sufficiently high performance of less than f/2.2, compact size of 3.3 mm (1st surf. to image), and wide field angle of more than 30 deg. compared with the specifications of a single lens. By proper choice of the aspheric and DOE surface which has very large negative dispersion, we can correct chromatic and high order aberrations through the optimization technique. From Seidel third order aberration theory and Sweatt modeling, the initial data and surface configurations, that is, the combination condition of the DOE and the aspherical surface are obtained. However, due to the consideration of diffraction efficiency of a DOE, we can choose only four cases as the optimization input, and present the best solution after evaluating and comparing those four cases. On the other hand, we also report dramatic improvement in optical performance by inserting another refractive lens (so-called, field flattener), that keeps the refractive power of an original DOE lens and makes the petzval sum zero in the original DOE lens system. ystem.

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Study on Close-Up Shots in Film (2015) (영화 <사도>(2015)의 클로즈업 쇼트 연구)

  • Lee, A-Young
    • The Journal of the Korea Contents Association
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    • v.16 no.7
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    • pp.609-621
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    • 2016
  • A close-up shot, capturing all the fine details of an actor's face by filling up the frame, expresses an actor's performance more realistically than a stage where a living actor performs on. This is because a close-up generates an impact with its specific images and meanings seizing the attention of the audience and conjures up a psychological effect as if an actor's face is directly communicating with the audience at a minimum distance. Therefore, this study analyzed the film to examine the photographic effect and acting effect of close-up shots and recommend the need for acting training thereof. The film was selected since Song Kang-ho, to add more realism to his character acted going back and forth 20 years of age with a special makeup on face, his facial expressions, gestures, props in close-up successfully helped deliver the actor's performance by revealing the character's personality and emotions of the film, and generated an array of linguistic, visual and emotional meanings which are the key to film acting. This study is expected to contribute to helping actors to learn about the effect of close-ups and the key to film acting and find effective ways to express themselves in front of the camera.

An Web-based Training of a short bamboo flute performance by using UCC (UCC를 활용한 단소 실기 원격 교육)

  • Lee, Yong-Bae;Lim, Sung-Joon
    • Journal of The Korean Association of Information Education
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    • v.11 no.4
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    • pp.471-482
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    • 2007
  • These days UCC(User-created content) is being made and shared increasingly in entertainment and sports area, but its life cycle seems to be very short and the cases that it is used for an education or a learning purposes are not common yet. In this study a new methodology is suggested for adapting a UCC to a distance education. A teacher upload the movie that he or she made for the distance education system, so the students can carry out the self-centered learning procedure. After that, the students send their own movie files to the teacher, and get a feedback from the teacher as a evaluation of the course. In this study a distance education system was established as a prototype, and a short bamboo flute class was chosen for this study from the specialty developmental education program of the elementary school. According to the result of the questionnaire the students thought that their performance skill was improved a lot and they were satisfied with the learning program and the method of evaluation. They also answered that their skills dealing with a camera, a camcorder and a computer got much better. Moreover, most of the students thought that the relationships with their friends and their parents got better also because they spent lots of time together making and watching the movie files for this education program.

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A Study on the Restoration of a Low-Resoltuion Iris Image into a High-Resolution One Based on Multiple Multi-Layered Perceptrons (다중 다층 퍼셉트론을 이용한 저해상도 홍채 영상의 고해상도 복원 연구)

  • Shin, Kwang-Yong;Kang, Byung-Jun;Park, Kang-Ryoung;Shin, Jae-Ho
    • Journal of Korea Multimedia Society
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    • v.13 no.3
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    • pp.438-456
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    • 2010
  • Iris recognition uses a unique iris pattern of user to identify person. In order to enhance the performance of iris recognition, it is reported that the diameter of iris region should be greater than 200 pixels in the captured iris image. So, the previous iris system used zoom lens camera, which can increase the size and cost of system. To overcome these problems, we propose a new method of enhancing the accuracy of iris recognition on low-resolution iris images which are captured without a zoom lens. This research is novel in the following two ways compared to previous works. First, this research is the first one to analyze the performance degradation of iris recognition according to the decrease of the image resolution by excluding other factors such as image blurring and the occlusion of eyelid and eyelash. Second, in order to restore a high-resolution iris image from single low-resolution one, we propose a new method based on multiple multi-layered perceptrons (MLPs) which are trained according to the edge direction of iris patterns. From that, the accuracy of iris recognition with the restored images was much enhanced. Experimental results showed that when the iris images down-sampled by 6% compared to the original image were restored into the high resolution ones by using the proposed method, the EER of iris recognition was reduced as much as 0.133% (1.485% - 1.352%) in comparison with that by using bi-linear interpolation

An Illumination-Robust Driver Monitoring System Based on Eyelid Movement Measurement (조명에 강인한 눈꺼풀 움직임 측정기반 운전자 감시 시스템)

  • Park, Il-Kwon;Kim, Kwang-Soo;Park, Sangcheol;Byun, Hye-Ran
    • Journal of KIISE:Software and Applications
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    • v.34 no.3
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    • pp.255-265
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    • 2007
  • In this paper, we propose a new illumination-robust drowsy driver monitoring system with single CCD(Charge Coupled Device) camera for intelligent vehicle in the day and night. For this system that is monitoring driver's eyes during a driving, the eye detection and the measure of eyelid movement are the important preprocesses. Therefore, we propose efficient illumination compensation algorithm to improve the performance of eye detection and also eyelid movement measuring method for efficient drowsy detection in various illumination. For real-time application, Cascaded SVM (Cascaded Support Vector Machine) is applied as an efficient eye verification method in this system. Furthermore, in order to estimate the performance of the proposed algorithm, we collect video data about drivers under various illuminations in the day and night. Finally, we acquired average eye detection rate of over 98% about these own data, and PERCLOS(The percentage of eye-closed time during a period) are represented as drowsy detection results of the proposed system for the collected video data.

HMM-based Intent Recognition System using 3D Image Reconstruction Data (3차원 영상복원 데이터를 이용한 HMM 기반 의도인식 시스템)

  • Ko, Kwang-Enu;Park, Seung-Min;Kim, Jun-Yeup;Sim, Kwee-Bo
    • Journal of the Korean Institute of Intelligent Systems
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    • v.22 no.2
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    • pp.135-140
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    • 2012
  • The mirror neuron system in the cerebrum, which are handled by visual information-based imitative learning. When we observe the observer's range of mirror neuron system, we can assume intention of performance through progress of neural activation as specific range, in include of partially hidden range. It is goal of our paper that imitative learning is applied to 3D vision-based intelligent system. We have experiment as stereo camera-based restoration about acquired 3D image our previous research Using Optical flow, unscented Kalman filter. At this point, 3D input image is sequential continuous image as including of partially hidden range. We used Hidden Markov Model to perform the intention recognition about performance as result of restoration-based hidden range. The dynamic inference function about sequential input data have compatible properties such as hand gesture recognition include of hidden range. In this paper, for proposed intention recognition, we already had a simulation about object outline and feature extraction in the previous research, we generated temporal continuous feature vector about feature extraction and when we apply to Hidden Markov Model, make a result of simulation about hand gesture classification according to intention pattern. We got the result of hand gesture classification as value of posterior probability, and proved the accuracy outstandingness through the result.