• Title/Summary/Keyword: In-depth Analysis

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Analysis of Gradually Varied Flow Considering Relative Depth in Circular Pipe (원형관에서 상대수심을 고려한 점변류 해석)

  • Kim, Minhwan;Park, Junghee;Song, Changsoo
    • Journal of Korean Society of Water and Wastewater
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    • v.21 no.3
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    • pp.287-294
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    • 2007
  • When we use the circular pipes for wastewater and storm water, we should be known the characteristics of the flow for accurate design. To elevate the design accuracy, we want to know the profile of flow. The roughness coefficient in the Manning equation is constant, but in actuality changed with the relative depth in circular pipe. This study was conducted to calculate the relative normal depth in changing the roughness coefficient (named relative roughness coefficient) with the relative depth in the analysis of gradually varied flow in the circular pipe by Newton-Raphson method. We performed the analysis of gradually varied flow using the relative normal depth and the relative roughness coefficient. We presented the 12 flow profiles with the relative depth and the relative roughness coefficient in circular pipe. The flow classification considering relative depth in circular pipe is available to analyse gradually varied flow profiles.

Compositional SIMS Depth Profiling of CIGS film

  • Kim, Gyeong-Jung;Hwang, Hye-Hyeon;Jang, Jong-Sik;Jeong, Yong-Deok
    • Proceedings of the Korean Vacuum Society Conference
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    • 2011.02a
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    • pp.367-367
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    • 2011
  • CIGS solar cell with copper, indium, gallium and selenium is a second generation solar cells for the lowering of the manufacturing cost. The relative ratio of the four elements is one of the most important measurement issues because the photovoltaic property of CIGS solar cell depends on the crystalline structure of the CIGS layer. However, there is no useful analysis method for the composition of the CIGS layer. Recently, AES depth profiling analysis of CIGS films has been studied with a reference material certified by inductively coupled plasma optical emission spectroscopy. However, there are some problems in AES depth profiling analysis of CIGS films. In this study, the in-depth profiling analysis was investigated by secondary ion mass spectrometry (SIMS) depth profiling analysis. We will present the compositional depth profiling of CIGS films by SIMS and its applications for the development of CIGS solar cells with high efficiency.

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A Relative Study on the Displacement of Earth Retaining Wall by 2 and 3 Dimentional Analysis (2차원 및 3차원 해석에 의한 토류벽의 변위에 관한 비교 연구)

  • Park, Chun-Sik;Park, Hae-Chan;Kim, Jong-Hwan;Park, Young-Jun
    • Proceedings of the Korean Geotechical Society Conference
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    • 2010.03a
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    • pp.801-810
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    • 2010
  • Until now, design of Earth Retaining is practiced by 2nd dimensional analysis for convenience of analysis and time saving. However, the construction field is 3rd dimension, in this study, practised the 3rd dimensional analysis which can reflect the field condition more exactly the scope of earth retaining wall, and researched about the effective and economical way of design, compared and reviewed with the results, by practising both the 2nd and 3rd dimensional analysis. existing 2nd dimension. the depth of excavation, depth of embedded and soil condition. As result, under the whole conditions, more displacement came to appear to the value as result of 3rd dimensional analysis more than the result of 2nd dimensional analysis. Accordingly, the displacement by the 2nd dimension analysis is underestimated. Moreover, results of 2nd and 3rd dimensional analysis, there is no difference at displacement, when the depth of embedded is 0.5H, 1.0H and 1.5H, but Displacement of 1.5H is smaller than 0.5H, 1.0H. That is, the bigger the depth of embedded becomes, the displacement of Earth Retaining Wall appeared smaller. The displacement of earth retaining wall according to depth of excavation appeared bigger, when the depth of excavation is increased. In the meantime, when the soil condition is different, in the 2nd dimensional analysis, the displacement appeared biggest, in case of the clay layer, but in the 3rd dimensional analysis, in the beginning of excavating, the displacement of earth retaining wall appeared bigger in case of clay layer, but as excavating is in progress, the displacement of both compound soil layer and sand layer appeared big.

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A Relative Study on the Displacement of Earth Retaining Wall by 2 and 3 Dimensional Analysis (2차원 및 3차원 해석에 의한 토류벽의 변위에 관한 비교 연구)

  • Kim, Jong-Hwan;Park, Choon-Sik
    • Proceedings of the Korean Geotechical Society Conference
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    • 2010.09b
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    • pp.181-185
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    • 2010
  • Until now, design of Earth Retaining is practiced by 2 dimensional analysis for convenience of analysis and time saving. However, the construction field is 3 dimension, in this study, practised the 3 dimensional analysis which can reflect the field condition more exactly the scope of earth retaining wall, and researched about the effective and economical way of design, compared and reviewed with the results, by practising both the 2 and 3 dimensional analysis. existing 2 dimension. the depth of excavation, depth of embedded and soil condition. As result, under the whole conditions, more displacement came to appear to the value as result of 3 dimensional analysis more than the result of 2nd dimensional analysis. Accordingly, the displacement by the 2 dimension analysis is underestimated. Moreover, results of 2 and 3 dimensional analysis, there is no difference at displacement, when the depth of embedded is 0.5H and 1.0H, but Displacement of 1.5H is smaller than 0.5H, 1.0H. That is, the bigger the depth of embedded becomes, the displacement of Earth Retaining Wall appeared smaller. The displacement of earth retaining wall according to depth of excavation appeared bigger, when the depth of excavation is increased. In the meantime, when the soil condition is different, in the 2 dimensional analysis, the displacement appeared biggest, in case of the clay layer, but in the 3 dimensional analysis, in the beginning of excavating, the displacement of earth retaining wall appeared bigger in case of clay layer, but as excavating is in progress, the displacement of both compound soil layer and sand layer appeared big.

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Repeatability Test for the Asymmetry Measurement of Human Appearance using General-purpose Depth Cameras (범용 깊이 카메라를 이용한 인체 외형 비대칭 측정의 반복성 평가)

  • Jang, Jun-Su
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.30 no.3
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    • pp.184-189
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    • 2016
  • Human appearance analysis is an important part of both eastern and western medicine fields, such as Sasang constitutional medicine, rehabilitation medicine, dental medicine, and etc. By the rapid growing of depth camera technology, 3D measuring becomes popular in many applications including medical area. In this study, the possibility of using depth cameras in asymmetry analysis of human appearance is examined. We introduce the development of 3D measurement system using 2 Microsoft Kinect depth cameras and fully automated asymmetry analysis algorithms based on computer vision technology. We compare the proposed automated method to the manual method, which is usually used in asymmetry analysis. As a measure of repeatability, standard deviations of asymmetry indices are examined by 10 times repeated experiments. Experimental results show that the standard deviation of the automated method (1.00mm for face, 1.22mm for body) is better than that of the manual method (2.06mm for face, 3.44mm for body) for the same 3D measurement. We conclude that the automated method using depth cameras can be successfully applicable to practical asymmetry analysis and contribute to reliable human appearance analysis.

Precision Analysis of the Depth Measurement System Using a Single Camera with a Rotating Mirror (회전 평면경과 단일 카메라를 이용한 거리측정 시스템의 정밀도 분석)

  • ;;;Chun Shin Lin
    • The Transactions of the Korean Institute of Electrical Engineers D
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    • v.52 no.11
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    • pp.626-633
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    • 2003
  • Theoretical analysis of the depth measurement system with the use of a single camera and a rotating mirror has been done. A camera in front of a rotating mirror acquires a sequence of reflected images, from which depth information is extracted. For an object point at a longer distance, the corresponding pixel in the sequence of images moves at a higher speed. Depth measurement based on such pixel movement is investigated. Since the mirror rotates along an axis that is in parallel with the vertical axis of the image plane, the image of an object will only move horizontally. This eases the task of finding corresponding image points. In this paper, the principle of the depth measurement-based on the relation of the pixel movement speed and the depth of objects have been investigated. Also, necessary mathematics to implement the technique is derived and presented. The factors affecting the measurement precision have been studied. Analysis shows that the measurement error increases with the increase of depth. The rotational angle of the mirror between two image-takings also affects the measurement precision. Experimental results using the real camera-mirror setup are reported.

A Local Feature-Based Robust Approach for Facial Expression Recognition from Depth Video

  • Uddin, Md. Zia;Kim, Jaehyoun
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.10 no.3
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    • pp.1390-1403
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    • 2016
  • Facial expression recognition (FER) plays a very significant role in computer vision, pattern recognition, and image processing applications such as human computer interaction as it provides sufficient information about emotions of people. For video-based facial expression recognition, depth cameras can be better candidates over RGB cameras as a person's face cannot be easily recognized from distance-based depth videos hence depth cameras also resolve some privacy issues that can arise using RGB faces. A good FER system is very much reliant on the extraction of robust features as well as recognition engine. In this work, an efficient novel approach is proposed to recognize some facial expressions from time-sequential depth videos. First of all, efficient Local Binary Pattern (LBP) features are obtained from the time-sequential depth faces that are further classified by Generalized Discriminant Analysis (GDA) to make the features more robust and finally, the LBP-GDA features are fed into Hidden Markov Models (HMMs) to train and recognize different facial expressions successfully. The depth information-based proposed facial expression recognition approach is compared to the conventional approaches such as Principal Component Analysis (PCA), Independent Component Analysis (ICA), and Linear Discriminant Analysis (LDA) where the proposed one outperforms others by obtaining better recognition rates.

Auto-Covariance Analysis for Depth Map Coding

  • Liu, Lei;Zhao, Yao;Lin, Chunyu;Bai, Huihui
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.8 no.9
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    • pp.3146-3158
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    • 2014
  • Efficient depth map coding is very crucial to the multi-view plus depth (MVD) format of 3-D video representation, as the quality of the synthesized virtual views highly depends on the accuracy of the depth map. Depth map contains smooth area within an object but distinct boundary, and these boundary areas affect the visual quality of synthesized views significantly. In this paper, we characterize the depth map by an auto-covariance analysis to show the locally anisotropic features of depth map. According to the characterization analysis, we propose an efficient depth map coding scheme, in which the directional discrete cosine transforms (DDCT) is adopted to substitute the conventional 2-D DCT to preserve the boundary information and thereby increase the quality of synthesized view. Experimental results show that the proposed scheme achieves better performance than that of conventional DCT with respect to the bitrate savings and rendering quality.

Precision Analysis of a Single Camera-based Depth Measurement System using the Reflected Images of a Rotating Mirror (회전 평면경의 반사 영상을 이용한 단일 카메라 시스템의 거리측정 정밀도 분석)

  • 나상익;손흥락;김형석
    • Proceedings of the IEEK Conference
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    • 2003.07e
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    • pp.2323-2326
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    • 2003
  • Theoretical analysis of the depth measurement system with the use of a single camera and a rotating mirror has hem done. A camera in front of a rotating mirror acquires a sequence of reflected images, from which depth information is extracted. For an object pint at a longer distance, the corresponding pixel in the sequence of images moves at a higher speed. In this paper, the principle d the depth measurement-based on the relation of the pixel movement speed and the depth of objects have been investigated. Also, necessary mathematics to implement the technique is derived and presented. The factors affecting the measurement precision have been studied Analysis shows that the measurement m increases with the increase of depth. The rotational angle of the mirror between two image-takings also affects the measurement precision. Experimental results using the real camera-mirror setup are reported.

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Correlation Analysis between Crack Depth of Concrete and Characteristics of Images (콘크리트 균열 깊이와 이미지 특성정보간의 상관성 분석)

  • Jung, Seo-Young;Yu, Jung-Ho
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2021.05a
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    • pp.162-163
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    • 2021
  • Currently, the depth of cracks is measured using ultrasonic detectors in maintenance practice. This method consists of measuring the depth of cracks by attaching ultrasonic depth measuring equipment to the concrete surface, and there are restrictions on the timing and location of the inspection. These limitations can be addressed through the development of image-based crack depth measurement AI technology. If crack depth measurements are made based on images, restrictions on the timing and location of inspections can be lifted because images acquired with simple filming equipment can be used as input information. To efficiently develop these artificial intelligence technologies, it is essential to identify the interrelationship between crack depth measurements and image characteristic information. Thus, this study is a basic study of the development of image-based crack depth measurement AI technology and aims to identify image characteristic information related to crack depth.

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