• Title/Summary/Keyword: 박정현

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Accuracy Analysis of GPS Absolute Positioning (GPS 절대측위 정확도 분석)

  • 강준묵;김욱남;박정현;이은수
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.19 no.1
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    • pp.1-8
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    • 2001
  • The aim of this study is to know the GPS absolute positioning accuracy after discontinuing of Selective Availability (SA). The GPS satellite clock errors and the observation station coordinates were calculated using GPS C/A code pseudorange and compared with the JPL precise ephemerides and the previous known coordinates. As the results, the correction or the GPS clock errors in SA-on is about $\pm$40m but in SA-off $\pm$2m. The 95% probable errors for the measurements in SA-on are about $\pm$65m but in SA-off $\pm$10m in X, Y and SA-off $\pm$15m in Z.

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Development of a GPS Baseline Analysis Software for L1 Carrier Phase Using LAMBDA Method (LAMBDA 기법을 활용한 L1 반송파의 GPS 기선해석 프로그램 개발)

  • 박정현;이용욱;권재현;강준묵
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.21 no.2
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    • pp.173-180
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    • 2003
  • As the utility value of GPS in surveying field is on the increase after the conversion into the world geodetic system, most of the baseline processing programs seeking the relative baseline vector for the roving point based on the base point are dependent on the foreign software, and such dependence remains a stumbling block to its wide application. In this study an algorithm was established settling ambiguity through LAMBDA techniques and the baseline processing program was developed for Ll carrier phase using visual c++ 6.0, which is an object-oriented language. And the developed program proved that it maintained a difference of less than 4.9 cm over the short baseline of 4.9 km or shorter when compared with other commercialized programs.

The Precision Analysis of Point Positioning Using GPS/GLONASS (GPS/GLONASS 조합에 의한 절대측위 정밀도 분석)

  • 강준묵;이용욱;박정현
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.19 no.1
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    • pp.9-17
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    • 2001
  • GPS is an efficient system in surveying and car navigation. but it is difficult to catch minimum number of satellite when it is hindered by obstacle such as city area. GLONASS system doesn't have perfect constellation yet, but it has many similarities with GPS system in principle of point positioning and signal system. so, it is expected to be much efficient when it is used with GPS system. For the purpose of this, the coordinates of GPS and GLONASS system, the quality of time and frequency was investigated, and the algorithm of point positioning was made. also, the efficiency of GPS/GLONASS combination was presented by analysing the precision of 3D point positioning using C/A code and Yuma satellite orbit information.

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A Device of Static Buffer Overflow Detection by using Function Summary and Tracking Information Flow of Buffer Domain (함수요약 및 버퍼의 도메인 정보흐름 추적에 의한 정적 버퍼넘침 탐지방안)

  • Lee, Hyung-Bong;Park, Jeong-Hyun;Park, Hyun-Mee
    • Journal of KIISE:Computing Practices and Letters
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    • v.7 no.6
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    • pp.703-714
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    • 2001
  • In C language, a local buffer overflow in stack can destroy control information stored near the buffer. In case the buffer overflow is used maliciously to overwrite the stored return address, the system is exposed to serious security vulnerabilities. This paper analyzes the process of buffer overflow hacking and methodologies to avoid the attacks in details. And it proposes a device of static buffer overflow detection by using function summary and tracking information flow of buffer domain at assembly source code level(SASS, Static Assembly Source code Scanner) and then show the feasibility and validity of it by implementing a prototype in Pentium based Linux environment.

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Maintenance Method of Mail Sorting Machine Based on FMEA (FMEA 기반 우편 기계 유지 보수 방법)

  • Park, Jeong-Hyun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.11 no.5
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    • pp.1601-1607
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    • 2010
  • This paper presents FMEA (Failure Mode Effect Analysis) for maintenance of mail sorting machine which is for automatic sorting of mail. We suggest the update method of regular diagnosis item and period for maintenance of mail sorting machine using the risk priority number which is calculated by severity, occurrence, and detection of failure mode of mail sorting machine, and shows FMEA adoption example of letter sorting machine. This paper also describes the current maintenance system and status of mail sorting machine in the domestic postal logistics environment, and FMEA adoption step. The proposed maintenance using FMEA will be adapted for more easy and efficiency maintenance of mail sorting machine.

Correlation factors to oral health-related quality of life in Chinese students studying in Korea (중국인 유학생의 구강건강관련 삶의 질에 미치는 영향요인)

  • Park, Jung-Hyun;Yu, Byeng-Chul;Park, Min-Koung;Cho, Mi-Suk
    • Journal of Korean society of Dental Hygiene
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    • v.14 no.4
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    • pp.511-518
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    • 2014
  • Objectives : The purpose of this study is to investigate the correlation factors to oral health-related quality of life in Chinese students studyng in Korea. Methods : A self-reported questionnaire was filled out by 231 students from November, 2012 to January, 2013. Data were analyzed by t-test, one way ANOVA, and Duncan post-hoc test using SPSS version 19.0. Results : Male students and short period staying students tended to have a higher quality of life. Smokers and large city dwellers tended to have a low oral health-related quality of life(p<0.05). The oral health-related quality of life in Chinese students in Korea was closely related to necessity of dental treatment and past experience of dental treatment services(p<0.05). Conclusions : To improve the oral health-related quality of life in foreign students, it is necessary to provide the early prevention of dental caries and periodontal diseases through the systematic and professional dental health care delivery program for the foreign students studying in Korea.

A Study on DGPS/GIS-based Vehicle Control for Safe Driving (안전주행을 위한 DGPS/GIS 기반의 차량제어 연구)

  • Lee, Kwanghee;Bak, Jeong-Hyeon;Lee, Chul-Hee
    • Transactions of the Korean Society of Automotive Engineers
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    • v.21 no.5
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    • pp.54-58
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    • 2013
  • In recent days, vehicles have become equipped with electric systems that assist and help drivers driving safe by reducing possible accidents. LDWS(Lane Departure Warning System) and LKAS(Lane Keeping Assistant System) are involved in assist systems, especially for lateral motion of vehicles. Sudden and inattentive lateral motion of vehicles due to drivers' fatigue, illness, inattention, and drowsiness are major causes of accidents in highway. LDWS and LKAS provide drivers with warnings or assisting power to reduce any possibilities of accidents. In order to prevent or minimize the possibilities of accidents, lateral motion control of vehicles has been introduced in this research. DGPS/RTK(Differential Global Positioning System/Real Time Kinematics) and GIS(Geographic Information System) have been used to obtain the current position of vehicles and decide when activate controlling lateral motion of vehicles. The presented lateral motion control has been validated with actual vehicle tests.

Planar Texture Replacement in Spherical Images using Cubemap (큐브맵을 사용한 구면 영상에서의 평면 텍스처 대치)

  • Park, Jeong-Hyeon;Park, Jong-Seung
    • Journal of Korea Game Society
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    • v.17 no.6
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    • pp.153-164
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    • 2017
  • In spherical panoramic images, SURF, a feature description method for planar patterns, does not work correctly due to heavy spherical distortion. Since a plane pattern is distorted in a spherical image, the pattern search and replacement in a spherical panoramic image should be treated differently from the case of the planar image. This paper proposes a planar texture replacement method, which transforms a spherical panoramic image into a cubemap panoramic image, searches a pattern using SURF, replaces a plane pattern, and then converts it into a spherical panoramic image.

Review on the Research Related to Bangpungtongseong-san(Bofutsusho-san) in Korea (방풍통성산 관련 연구 분석)

  • Park, Jung-Hyun;Lee, Myeong-Jong;Kim, Ho-Jun
    • Journal of Korean Medicine Rehabilitation
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    • v.21 no.2
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    • pp.189-202
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    • 2011
  • Objectives : The objective of the review was to research related to Bangpungtongseong-san(Bofutsusho-san) in oriental medicine in South Korea. Methods : Oriental medicine advanced searching integrated system(OASIS), 4 Korean medical databases and 5 Korean medical journals were searched by using search terms as Bangpungtongseong-san or Bofutsusho-san. In order to see detail review, we classified all the searched studies into types, methods, purposes, outcome measures and main conclusions. Results : We found out total thirty one studies. There were seventeen experimental studies, four clinical studies, seven case reports and three literature reviews. The main thesis were related to metabolic syndrome, including obesity, hyperlipidemia and hypertension, etc. The studies about the safety and toxicity concluded Bangpungtongseong-san did not seem to affect toxicity. In the outcome measure, body mass index, serum biochemical analysis, cell study, abdominal computed tomography(CT) and bioelectrical impedance analysis were used. Conclusions : To improve more objective and continuous research in oriental medicine, further rigorous clinical trials using herbal medicines should be performed.

Electrical Characteristic Analysis of IGZO TFT with Poly (4-vinylphenol) Gate Insulator according to Annealing Temperature (Poly (4-vinylphenol) 게이트 절연체를 적용한 IGZO TFT의 열처리 온도에 따른 전기적 특성 분석)

  • Park, Jung Hyun;Jeong, Jun Kyo;Kim, Yu Jeong;Jun, Jung Byung;Lee, Ga Won
    • Journal of the Semiconductor & Display Technology
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    • v.16 no.1
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    • pp.97-101
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    • 2017
  • In this paper, IGZO thin film transistor (TFT) was fabricated with cross-linked Poly (4-vinylphenol) (PVP) gate dielectric for flexible, transparent display applications. The PVP is one of the candidates for low-temperature gate insulators. MIM structure was fabricated to measure the leakage current and evaluate the insulator properties according to the annealing temperature. Low leakage current ( <0.1nA/cm2 @ 1MV/cm ) was observed at $200^{\circ}C$ annealing condition and decreases much more as the annealing temperature increases. The electrical characteristics of IGZO TFT such as subthreshold swing, mobility and ON/OFF current ratio were also improved, which shows that the performance of IGZO TFTs with PVP can be enhanced by reducing the amount of incomplete crosslinking in PVP.

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