• Title/Summary/Keyword: post processing

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Improvement of GPS positioning accuracy by static post-processing method (정적 후처리방식에 의한 GPS의 측위정도 개선)

  • 김민선;신현옥
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.39 no.4
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    • pp.251-261
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    • 2003
  • To measure the GPS position accuracy and its distribution according to the length of the baseline, 30 minutes to 24 hours observations at the fixed location were conducted with two GPS receivers (Ll, 12 channels) on May 29 to June 2, 2002. The GPS data received at the reference station, the rover station and the ordinary times GPS observation station operated by the National Geography Institute in Korea were processed in kinematic and static post-processing methods with a post -processing software. The results obtained are summarized as follows: 1. The number of the satellite that could be observed continuously more than six hours was 16 and most of these satellites were positioned at east-west direction on May 31, 2002. The number of the satellite observed and the geometric dilution of precision (GDOP) determined by the average of every 10 minute for the day were 8 and 3.89, respectively. 2. Both the average GPS positions before and after post-processing were shifted (standalone: 1.17 m, post -processing: 0.43m) to the south and west. The twice distance root mean square (2drms) measured with standalone was 6.65m. The 2drms could be reduced to 33.8% (standard deviation 0=17.2) and 5.3% (0=2.2) of standalone by the kinematic and the static post-processing methods, respectively. 3. The relationship between the length of the baseline x (km) and the 2drms y (m) obtained by the static post-processing method was y=0.00l6x+0.006 $(R^2=0.87)$. In the case of the positioning with the static post-processing method using the GPS receiver, it was found that a positioning within 20cm 2drms was possible when the length of the baseline was less than 100km and the receiving time of the GPS is more than 30 minutes.

Development of Internet Based GPS Data Processing Service

  • Kim, Sang-Ho;Park, Kwan-Dong;Kim, Hye-In
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • v.2
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    • pp.291-295
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    • 2006
  • As GPS equipments improve, one can acquire GPS data easily in the field. However, to obtain precise and accurate coordinates, post processing is additionally required and the processing needs high degree of skills. Besides, it is very common that we can't operate processing software in the field because required system environment is usually not prepared. The aim of this study is the development of internet-based GPS data processing service. For post processing, we use GIPSY developed by JPL. It has many advantages such as precise point positioning, which enables a rapid determination of receiver positions. The developed service in this study proceeds as following orders by interlocking GIPSY and internet service on a Linux platform: Users upload raw data files on the internet, then GIPSY runs automatically and then the user get the result in the field. We use an Apache Web Server as a hosting program and PHP is used in coding web pages.

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Radar Signal Processor Design Using FPGA (FPGA를 이용한 레이더 신호처리 설계)

  • Ha, Changhun;Kwon, Bojun;Lee, Mangyu
    • Journal of the Korea Institute of Military Science and Technology
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    • v.20 no.4
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    • pp.482-490
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    • 2017
  • The radar signal processing procedure is divided into the pre-processing such as frequency down converting, down sampling, pulse compression, and etc, and the post-processing such as doppler filtering, extracting target information, detecting, tracking, and etc. The former is generally designed using FPGA because the procedure is relatively simple even though there are large amounts of ADC data to organize very quickly. On the other hand, in general, the latter is parallel processed by multiple DSPs because of complexity, flexibility and real-time processing. This paper presents the radar signal processor design using FPGA which includes not only the pre-processing but also the post-processing such as doppler filtering, bore-sight error, NCI(Non-Coherent Integration), CFAR(Constant False Alarm Rate) and etc.

Study on the Development of Post-Processor for 5-Axis NC Machining (5축 가공용 Post-Processor 개발에 관한 연구)

  • Jo, E.J.;Hwang, J.D.;Jung, Y.G.
    • Transactions of the Korean Society of Machine Tool Engineers
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    • v.15 no.3
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    • pp.53-58
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    • 2006
  • This study deals with the method of post-processing in the automatic tool path generation for 5-axis NC machining. The 5-axis NC machining cannot only cope with the manufacturing of complicated shapes, but also offers numerous advantages such as reasonable tool employment, great reduction of set-up process and so on. Thus 5-axis NC machining has been used for aircraft parts, mold and die as well as for complicated shapes such as impeller, propeller and rotor. However, most of the present CAM systems for 5-axis NC machining have limited functions in terms of tool collision, machine limits and post-processing. Especially 5-axis machine configurations are various according to the method which the rotational axes are adapted with the table and spindle. For that reason, In many cases the optimal numerical control (NC) data cannot be obtained or considerable time is consumed. To solve this problem, we applied a general post-processor for 5-axis NC machining. The validity of this post-processor should be experimentally confirmed by successfully milling to a helix shaped workpiece.

Study on the Development of Post-Processor for 5-Axis NC machining (5축가공용 Post-Processor 개발에 관한 연구)

  • Hwang J.D.;Jung Y.G.;Jung J.Y.
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2005.10a
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    • pp.370-374
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    • 2005
  • This study deals with the method of post-processing in the automatic tool path generation for 5-axis NC machining. The 5-axis NC machining cannot only cope with the manufacturing of complicated shapes, but also offers numerous advantages such as reasonable tool employment, great reduction of set-up process and so on. Thus 5-axis NC machining has been used fur aircraft parts, mold and die as well as for complicated shapes such as impeller, propeller and rotor. However, most of the present CAM systems for 5-axis NC machining have limited functions in terms of tool collision, machine limits and post-processing. Especially 5-axis machine configurations are various according to the method which the rotational axes are adapted with the table and spindle. For that reason, in many cases the optimal numerical control (NC) data cannot be obtained or considerable time is consumed. To solve this problem, we applied a general post-processor fur 5-axis NC machining. The validity of this post-processor should be experimentally confirmed by successfully milling to a helix shaped workpiece.

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Post-Processing of High-Speed Video-Laryngoscopic Images to Two-Dimensional Scanning Digital Kymographic Images (초고속 후두내시경 영상을 이용한 평면 스캔 비디오카이모그래피 영상 생성)

  • Cha, Wonjae;Wang, Soo-Geun;Jang, Jeon Yeob;Kim, Geun-Hyo;Lee, Yeon-Woo
    • Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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    • v.28 no.2
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    • pp.89-95
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    • 2017
  • Background and Objectives : High-speed videolaryngoscopy (HSV) is the only technique that captures the true intra-cycle vibratory behavior of the vocal folds by capturing full images of the vocal folds. However, it has problems of no immediate feedback during examination, considerable waiting time for digital kymography (DKG), recording duration limited to a few seconds, and extreme demands for storage space. Herein, we demonstrate a new post-processing method that converts HSV images to two-dimensional digital kymography (2D-DKG) images, which adopts the algorithm of 2D videokymography (2D VKG). Materials and Methods : HSV system was used to capture images of vocal folds. HSV images were post-processed in Kay image-process software (KIPS), and conventional DKG images were retrieved. Custom-made post-processing system was used to convert HSV images to 2D-DKG images. The quantitative parameters of the post-processed 2D-DKG images was validated by comparing these parameters with those of the DKG images. Results : Serial HSV images for all phases of vocal fold vibratory movement are included. The images were converted by the scanning method using U-medical image-process software. Similar to conventional DKG, post-processed 2D DKG image from the HSV image can provide quantitative information on vocal fold mucosa vibration, including the various vibratory phases. Differences in amplitude symmetry index, phase symmetry index, open quotient, and close quotient between 2D-DKG and DKG were analyzed. There were no statistical differences between the quantitative parameters of vocal fold vibratory movement in 2D-DKG and DKG. Conclusion : The post-processing method of converting HSV images to 2D DKG images could provide clinical information and storage economy.

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Comparison of Quality Properties of Rice Cultivars for Beverage Processing (음료가공을 위한 쌀 품종별 품질 특성 비교)

  • Shin, Dong-Sun;Sim, Eun Yeong;Lee, Seuk Ki;Choi, Hye-Sun;Park, Ji-Young;Woo, Koan Sik;Kim, Hyun-Joo;Cho, Dong Hwa;Oh, Sea Kwan;Han, Sang Ik;Park, Hye-Young
    • The Korean Journal of Food And Nutrition
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    • v.30 no.6
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    • pp.1260-1267
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    • 2017
  • The properties of rice were studied on five rice cultivars (Ilpumbyeo, Samkwang, Goami-4, Dodamssal, and Thai rice), and employed two kinds of saccharification treatment methods (treatment I : rice shape, treatment II: grinding rice shape). Thai rice showed differences in width and length when compared to other cultivars of rice, and the Goami 4 had the lowest thousand-grain weight. The Goami4 and Dodamssal each showed high contents of amylose and resistant starch, and the water absorption rate was close to maximum at 90 minutes as well as the highest level of Goami 4 at all times. The qualities of highest water-binding capacity, solubility and swelling power was most significant in Thai rice. The lowest hardness level of wet rice resulted in the lowest hydration-related characteristics. High amylose content rice, in particular, showed low sugar content and slightly increased sugar content as the saccharification process improved (treatment II). On the other hand, high amylose cultivars had the same high degree of hardness as boiled rice. From these results, the Dodamssal was found to have the lowest viscosity at all temperatures but highest viscosity during the saccharification process, suggesting it may be successfully implemented as a thickener in rice beverage processing. The purpose of this study was to attempt to provide basic data on the development of rice beverage manufacturing technology, based upon the quality characteristics related to beverage processing of rice cultivars.

Off-Site Distortion and Color Compensation of Underwater Archaeological Images Photographed in the Very Turbid Yellow Sea

  • Jung, Young-Hwa;Kim, Gyuho;Yoo, Woo Sik
    • Journal of Conservation Science
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    • v.38 no.1
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    • pp.14-32
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    • 2022
  • Underwater photographing and image recording are essential for pre-excavation survey and during excavation in underwater archaeology. Unlike photographing on land, all underwater images suffer various quality degradations such as shape distortions, color shift, blur, low contrast, high noise levels and so on. Outcome is very often heavily photographing equipment and photographer dependent. Excavation schedule, weather conditions, and water conditions can put burdens on divers. Usable images are very limited compared to the efforts. In underwater archaeological study in very turbid water such as in the Yellow Sea (between mainland China and the Korean peninsula), underwater photographing is very challenging. In this study, off-site image distortion and color compensation techniques using an image processing/analysis software is investigated as an alternative image quality enhancement method. As sample images, photographs taken during the excavation of 800-year-old Taean Mado Shipwrecks in the Yellow Sea in 2008-2010 were mainly used. Significant enhancement in distortion and color compensation of archived images were obtained by simple post image processing using image processing/analysis software (PicMan) customized for given view ports, lenses and cameras with and without optical axis offsets. Post image processing is found to be very effective in distortion and color compensation of both recent and archived images from various photographing equipment models and configurations. Merits and demerit of in-situ, distortion and color compensated photographing with sophisticated equipment and conventional photographing equipment, which requires post image processing, are compared.

A Study on Unstructured text data Post-processing Methodology using Stopword Thesaurus (불용어 시소러스를 이용한 비정형 텍스트 데이터 후처리 방법론에 관한 연구)

  • Won-Jo Lee
    • The Journal of the Convergence on Culture Technology
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    • v.9 no.6
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    • pp.935-940
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    • 2023
  • Most text data collected through web scraping for artificial intelligence and big data analysis is generally large and unstructured, so a purification process is required for big data analysis. The process becomes structured data that can be analyzed through a heuristic pre-processing refining step and a post-processing machine refining step. Therefore, in this study, in the post-processing machine refining process, the Korean dictionary and the stopword dictionary are used to extract vocabularies for frequency analysis for word cloud analysis. In this process, "user-defined stopwords" are used to efficiently remove stopwords that were not removed. We propose a methodology for applying the "thesaurus" and examine the pros and cons of the proposed refining method through a case analysis using the "user-defined stop word thesaurus" technique proposed to complement the problems of the existing "stop word dictionary" method with R's word cloud technique. We present comparative verification and suggest the effectiveness of practical application of the proposed methodology.

A Model for Post-processing of Speech Recognition Using Syntactic Unit of Morphemes (구문형태소 단위를 이용한 음성 인식의 후처리 모델)

  • 양승원;황이규
    • Journal of Korea Society of Industrial Information Systems
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    • v.7 no.3
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    • pp.74-80
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    • 2002
  • There are many researches on post-processing methods for the Korean continuous speech recognition enhancement using natural language processing techniques. It is very difficult to use a formal morphological analyzer for improving the speech recognition because the analysis technique of natural language processing is mainly for formal written languages. In this paper, we propose a speech recognition enhancement model using syntactic unit of morphemes. This approach uses the functional word level longest match which dose not consider spacing words. We describe the post-processing mechanism for the improving speech recognition by using proposed model which uses the relationship of phonological structure information between predicates md auxiliary predicates or bound nouns that are frequently occurred in Korean sentences.

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