• Title/Summary/Keyword: Time-Efficiency of Algorithm

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HEVC Encoder Optimization using Depth Information (깊이정보를 이용한 HEVC의 인코더 고속화 방법)

  • Lee, Yoon Jin;Bae, Dong In;Park, Gwang Hoon
    • Journal of Broadcast Engineering
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    • 제19권5호
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    • pp.640-655
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    • 2014
  • Many of today's video systems have additional depth camera to provide extra features such as 3D support. Thanks to these changes made in multimedia system, it is now much easier to obtain depth information of the video. Depth information can be used in various areas such as object classification, background area recognition, and so on. With depth information, we can achieve even higher coding efficiency compared to only using conventional method. Thus, in this paper, we propose the 2D video coding algorithm which uses depth information on top of the next generation 2D video codec HEVC. Background area can be recognized with depth information and by performing HEVC with it, coding complexity can be reduced. If current CU is background area, we propose the following three methods, 1) Earlier stop split structure of CU with PU SKIP mode, 2) Limiting split structure of CU with CU information in temporal position, 3) Limiting the range of motion searching. We implement our proposal using HEVC HM 12.0 reference software. With these methods results shows that encoding complexity is reduced more than 40% with only 0.5% BD-Bitrate loss. Especially, in case of video acquired through the Kinect developed by Microsoft Corp., encoding complexity is reduced by max 53% without a loss of quality. So, it is expected that these techniques can apply real-time online communication, mobile or handheld video service and so on.

DEVELOPMENT OF AN AMPHIBIOUS ROBOT FOR VISUAL INSPECTION OF APR1400 NPP IRWST STRAINER ASSEMBLY

  • Jang, You Hyun;Kim, Jong Seog
    • Nuclear Engineering and Technology
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    • 제46권3호
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    • pp.439-446
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    • 2014
  • An amphibious inspection robot system (hereafter AIROS) is being developed to visually inspect the in-containment refueling storage water tank (hereafter IRWST) strainer in APR1400 instead of a human diver. Four IRWST strainers are located in the IRWST, which is filled with boric acid water. Each strainer has 108 sub-assembly strainer fin modules that should be inspected with the VT-3 method according to Reg. guide 1.82 and the operation manual. AIROS has 6 thrusters for submarine voyage and 4 legs for walking on the top of the strainer. An inverse kinematic algorithm was implemented in the robot controller for exact walking on the top of the IRWST strainer. The IRWST strainer has several top cross braces that are extruded on the top of the strainer, which can be obstacles of walking on the strainer, to maintain the frame of the strainer. Therefore, a robot leg should arrive at the position beside the top cross brace. For this reason, we used an image processing technique to find the top cross brace in the sole camera image. The sole camera image is processed to find the existence of the top cross brace using the cross edge detection algorithm in real time. A 5-DOF robot arm that has multiple camera modules for simultaneous inspection of both sides can penetrate narrow gaps. For intuitive presentation of inspection results and for management of inspection data, inspection images are stored in the control PC with camera angles and positions to synthesize and merge the images. The synthesized images are then mapped in a 3D CAD model of the IRWST strainer with the location information. An IRWST strainer mock-up was fabricated to teach the robot arm scanning and gaiting. It is important to arrive at the designated position for inserting the robot arm into all of the gaps. Exact position control without anchor under the water is not easy. Therefore, we designed the multi leg robot for the role of anchoring and positioning. Quadruped robot design of installing sole cameras was a new approach for the exact and stable position control on the IRWST strainer, unlike a traditional robot for underwater facility inspection. The developed robot will be practically used to enhance the efficiency and reliability of the inspection of nuclear power plant components.

A Research on the Parametric Design Method in Pre-Design Phase for BIM application (BIM 적용을 위한 기획설계 단계의 파라메트릭 디자인기법에 대한 연구)

  • Ha, Seung-Beom
    • The Journal of the Convergence on Culture Technology
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    • 제7권1호
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    • pp.92-98
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    • 2021
  • Modern society needs constantly the rationality and the efficiency, and this flow of the time has become the paradigm of the whole society. This paradigm has a large influence on the architectural design and industry. Modern technology represented by the development of digital instrument and Information Technology through internet has created and developed two big trend, Parametric Design and BIM(Building information Modeling) in the architectural design and industry. These technologies, though created for different reasons, have a lot of influence on the architectural design and industry for a common purpose such as efficiency and rationality across the boundaries. In this context, this research will be embodied through the example about how parametric design should be made in the beginning of pre-design phase for BIM application. This research aims to consider the design process of Walt Diseny Consert Hall, the work of Frank O. Ghery, a deconstructivism architect, and to embody the shape of National Nederlanden Building in Prague, the Czech Republic, using parametric design tool in pre-design phase. This research later aims to be used as the basic data that can be applied to the entire architectural industry from a planning and a detailed design to a construction for the ultimate BIM application beyond the range of parametric design in pre-design phase. Later, the plan using the parametric design algorithm and BIM application in construction document phase will be conducted.

An Efficient Coding Technique of Holographic Video Signal using 3D Segment Scanning (분할영역의 3차원 스캐닝을 이용한 홀로그래픽 비디오 신호의 효율적인 부호화 기술)

  • Seo, Young-Ho;Choi, Hyun-Jun;Kim, Dong-Wook
    • The Journal of Korean Institute of Communications and Information Sciences
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    • 제32권2C호
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    • pp.132-140
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    • 2007
  • In this paper, we proposed a new technique to encode and decode the digital hologram. Since the digital hologram (or fringe pattern) is generated by interference of light, it has much different property from natural 2D (2 dimensional) images. First, we acquisite optical-sensed or computer-generated hologram by digital type, and then extract a chrominance component. The extracted digital hologram for coding is separated into segments to use multi-view properties. The segmented hologram shows the similar characteristics with picturing an object with 2D cameras in various point of view. Since fringe pattern is visually observed like as noise, we expect that the fringe pattern has poor coding efficiency. To obtain high efficiency, the segment is transformed with DCT (Discrete Cosine Transform) which resembles hologram generation process with high performance. Each transformed segment passes the 3D scanning process according to time and spatial correlation, and is organized into a video stream. Since the segment which correspond to frame of a video stream consists of the transformed coefficients with wide range of value, it is classified and re-normalized. Finally it is compressed with coding tools. The proposed algorithm illustrated that it has better properties for reconstruction of 16 times higher compression rate than the previous researches.

New Prefiltering Methods based on a Histogram Matching to Compensate Luminance and Chrominance Mismatch for Multi-view Video (다시점 비디오의 휘도 및 색차 성분 불일치 보상을 위한 히스토그램 매칭 기반의 전처리 기법)

  • Lee, Dong-Seok;Yoo, Ji-Sang
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • 제47권6호
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    • pp.127-136
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    • 2010
  • In multi-view video, illumination disharmony between neighboring views can occur on account of different location of each camera and imperfect camera calibration, and so on. Such discrepancy can be the cause of the performance decrease of multi-view video coding by mismatch of inter-view prediction which refer to the pictures obtained from the neighboring views at the same time. In this paper, we propose an efficient histogram-based prefiltering algorithm to compensate mismatches between the luminance and chrominance components in multi-view video for improving its coding efficiency. To compensate illumination variation efficiently, all camera frames of a multi-view sequence are adjusted to a predefined reference through the histogram matching. A Cosited filter that is used for chroma subsampling in many video encoding schemes is applied to each color component prior to histogram matching to improve its performance. The histogram matching is carried out in the RGB color space after color space converting from YCbCr color space. The effective color conversion skill that has respect to direction of edge and range of pixel value in an image is employed in the process. Experimental results show that the compression ratio for the proposed algorithm is improved comparing with other methods.

A Modified grid-based KIneMatic wave STOrm Runoff Model (ModKIMSTORM) (I) - Theory and Model - (격자기반 운동파 강우유출모형 KIMSTORM의 개선(I) - 이론 및 모형 -)

  • Jung, In Kyun;Lee, Mi Seon;Park, Jong Yoon;Kim, Seong Joon
    • KSCE Journal of Civil and Environmental Engineering Research
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    • 제28권6B호
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    • pp.697-707
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    • 2008
  • The grid-based KIneMatic wave STOrm Runoff Model (KIMSTORM) by Kim (1998) predicts the temporal variation and spatial distribution of overland flow, subsurface flow and stream flow in a watershed. The model programmed with C++ language on Unix operating system adopts single flowpath algorithm for water balance simulation of flow at each grid element. In this study, we attempted to improve the model by converting the code into FORTRAN 90 on MS Windows operating system and named as ModKIMSTORM. The improved functions are the addition of GAML (Green-Ampt & Mein-Larson) infiltration model, control of paddy runoff rate by flow depth and Manning's roughness coefficient, addition of baseflow layer, treatment of both spatial and point rainfall data, development of the pre- and post-processor, and development of automatic model evaluation function using five evaluation criteria (Pearson's coefficient of determination, Nash and Sutcliffe model efficiency, the deviation of runoff volume, relative error of the peak runoff rate, and absolute error of the time to peak runoff). The modified model adopts Shell Sort algorithm to enhance the computational performance. Input data formats are accepted as raster and MS Excel, and model outputs viz. soil moisture, discharge, flow depth and velocity are generated as BSQ, ASCII grid, binary grid and raster formats.

Development of an Optimization Model and Algorithm Based on Transportation Problem with Additional Constraints (추가 제약을 갖는 수송문제를 활용한 공화차 배분 최적화 모형 및 해법 개발)

  • Park, Bum Hwan;Kim, Young-Hoon
    • Journal of the Korean Society for Railway
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    • 제19권6호
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    • pp.833-843
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    • 2016
  • Recently, in the field of rail freight transportation, the number of trains dedicated for shippers has been increasing. These dedicated trains, which run on the basis of a contract with shippers, had been restricted to the transportation of containers, or so called block trains. Nowadays, such commodities have extended to cement, hard coal, etc. Most full freight cars are transported by dedicated trains. But, for empty car distribution, the efficiency still remains questionable because the distribution plan is manually developed by dispatchers. In this study, we investigated distribution models delineated in the KTOCS system which was developed by KORAIL as well as mathematical models considered in the state-of-the-art. The models are based on optimization models, especially the network flow model. Here we suggest a new optimization model with a framework of the column generation approach. The master problem can be formulated into a transportation problem with additional constraints. The master problem is improved by adding a new edge between the supply node and the demand node; this edge can be found using a simple shorted path in the time-space network. Finally, we applied our algorithm to the Korean freight train network and were able to find the total number of empty car kilometers decreased.

An Automatic Mobile Cell Counting System for the Analysis of Biological Image (생물학적 영상 분석을 위한 자동 모바일 셀 계수 시스템)

  • Seo, Jaejoon;Chun, Junchul;Lee, Jin-Sung
    • Journal of Internet Computing and Services
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    • 제16권1호
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    • pp.39-46
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    • 2015
  • This paper presents an automatic method to detect and count the cells from microorganism images based on mobile environments. Cell counting is an important process in the field of biological and pathological image analysis. In the past, cell counting is done manually, which is known as tedious and time consuming process. Moreover, the manual cell counting can lead inconsistent and imprecise results. Therefore, it is necessary to make an automatic method to detect and count cells from biological images to obtain accurate and consistent results. The proposed multi-step cell counting method automatically segments the cells from the image of cultivated microorganism and labels the cells by utilizing topological analysis of the segmented cells. To improve the accuracy of the cell counting, we adopt watershed algorithm in separating agglomerated cells from each other and morphological operation in enhancing the individual cell object from the image. The system is developed by considering the availability in mobile environments. Therefore, the cell images can be obtained by a mobile phone and the processed statistical data of microorganism can be delivered by mobile devices in ubiquitous smart space. From the experiments, by comparing the results between manual and the proposed automatic cell counting we can prove the efficiency of the developed system.

Text Region Extraction from Videos using the Harris Corner Detector (해리스 코너 검출기를 이용한 비디오 자막 영역 추출)

  • Kim, Won-Jun;Kim, Chang-Ick
    • Journal of KIISE:Software and Applications
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    • 제34권7호
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    • pp.646-654
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    • 2007
  • In recent years, the use of text inserted into TV contents has grown to provide viewers with better visual understanding. In this paper, video text is defined as superimposed text region located of the bottom of video. Video text extraction is the first step for video information retrieval and video indexing. Most of video text detection and extraction methods in the previous work are based on text color, contrast between text and background, edge, character filter, and so on. However, the video text extraction has big problems due to low resolution of video and complex background. To solve these problems, we propose a method to extract text from videos using the Harris corner detector. The proposed algorithm consists of four steps: corer map generation using the Harris corner detector, extraction of text candidates considering density of comers, text region determination using labeling, and post-processing. The proposed algorithm is language independent and can be applied to texts with various colors. Text region update between frames is also exploited to reduce the processing time. Experiments are performed on diverse videos to confirm the efficiency of the proposed method.

Recognition Method of Korean Abnormal Language for Spam Mail Filtering (스팸메일 필터링을 위한 한글 변칙어 인식 방법)

  • Ahn, Hee-Kook;Han, Uk-Pyo;Shin, Seung-Ho;Yang, Dong-Il;Roh, Hee-Young
    • Journal of Advanced Navigation Technology
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    • 제15권2호
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    • pp.287-297
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    • 2011
  • As electronic mails are being widely used for facility and speedness of information communication, as the amount of spam mails which have malice and advertisement increase and cause lots of social and economic problem. A number of approaches have been proposed to alleviate the impact of spam. These approaches can be categorized into pre-acceptance and post-acceptance methods. Post-acceptance methods include bayesian filters, collaborative filtering and e-mail prioritization which are based on words or sentances. But, spammers are changing those characteristics and sending to avoid filtering system. In the case of Korean, the abnormal usages can be much more than other languages because syllable is composed of chosung, jungsung, and jongsung. Existing formal expressions and learning algorithms have the limits to meet with those changes promptly and efficiently. So, we present an methods for recognizing Korean abnormal language(Koral) to improve accuracy and efficiency of filtering system. The method is based on syllabic than word and Smith-waterman algorithm. Through the experiment on filter keyword and e-mail extracted from mail server, we confirmed that Koral is recognized exactly according to similarity level. The required time and space costs are within the permitted limit.