• Title/Summary/Keyword: Datum

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An Experimental Study of Fatigue and Static Behavior for Composite Deck Member (복합재료 바닥판 부재의 정적 및 피로거동에 관한 시험적 연구)

  • Kim, Doo-Hwan;Kim, Young-Chan
    • Journal of the Korean Society of Hazard Mitigation
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    • v.11 no.2
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    • pp.15-21
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    • 2011
  • It is required to accumulate experimental datum that make the theories easy to general technicians in order to use composite material widely on construction field. Therefore, we intend to present base technologies that evaluate static and fatigue performance according to the FRP deck section and offer the basis datum for FRP deck analyses and the design standards. As results of static tests, it can be shown that specimen with fabric direction has higher rigidity than that with normal to fabric direction and convergence for the datum. Due to this reason, it has more stable behavior by structural characteristics of matrix arrangement during destruction. For the fatigue tests, we found that by increasing the number of test repetition, test specimen with fabric direction had an crack just before the destruction, and the contact surface was detached.

Study for the restoration of Gyeongcheonsa Pagoda - top of pagoda - (경천사(敬天寺) 10층석탑(層石塔) 복원(復原)에 관한 고찰 I - 상륜부(相輪部)를 중심으로 -)

  • Yi, Eun-Hui;Kim, Sa-Dug;Shin, Eun-Jeong
    • Korean Journal of Heritage: History & Science
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    • v.35
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    • pp.100-118
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    • 2002
  • Originally, Gyeongcheonsa pagoda was located in Busosan, Jungyeon-ri, Gwangdeok-myeon, Gaepung-gun, Gyeonggi-do,but it has suffered from being taken out to Japan illegally in 1907 and being returned to Korea in 1918. After returned to Korea, Gyeoncheonsa Pagoda had been neglected and restored in 1960. It had been exhibited outside the Gyeingbokgung Palace after restoration, but many problems were raised. It was taken to pieces in 1995 and it is conservation and restoring today. However, the top of pagoda is necessary to be researched about its archetype because the shapes of stupa in 1902 and in 1960(the shape of pagoda after restoration) are all different from its archetype. According to picture datum in 1902, the top of pagoda was a Korean building type on a 10 layered roof stone. On the other hand, when it was restored in 1960, cement suspected as a anda was taken place between Korean building type and a 10 layered roof stone. Therefore, I am going to examine Restoration of Gyeongcheonsa pagoda in this thesis. When we examine historical records of Geongcheonsa and datum of parts, we can know that the pagoda was established in 1348(Goryeo Dynasty) but it is difficult to know the truth of its establishment and demolition of Gyeongcheonsa-temple. Three ways to restore the top of the pagoda of Gyeoncheonsa Pagoda can be c o n s i d e r e d . First, Korean building type made by metals is located on a 10 layered roof stone, which is same to picture datum in 1902. Second, the shape of and a type, which is similar to the shape when it was restored in 1960's. Also it is similar to Lamapagoda type. Third, to restore the top of pagoda of gabled roof type, which is similar to the top of pagoda of Wongaksagi P agoda. However it is necessaray to exmamine functions about circle grooves hollowed out in a 10 layered roof stone in restoration. Also we need to find out the archetype of dragon sculpture through the dragon claws left on an edge of a 10 layered roof stone.

Boresight Calibration Comparison Using Geoid Models (지오이드 모델에 따른 Boresight 검정 비교)

  • So, Jae Kyeong;Park, Young Su;Won, Jae Ho;Yun, Hee Cheon
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.34 no.3
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    • pp.291-297
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    • 2016
  • Direct georeferencing has become widespread in the field of digital aerial photogrammetry; as a result, the boresight calibration has become an essential component of the procedure to calculating exterior orientation parameters of aerial photographs accurately. During this procedure, a reference is used for the height of the geoid model, and the calibration results can appear different depending on the geoid model. The exterior orientation parameters calculated through direct georeferencing during boresight calibration may have varied values according to the corresponding geoid model. With that in mind, the effects of the geoid model on the boresight calibration were analyzed through three different cases. The geoid models used in the experiments were EGM96, EGM08, and KNGeoid14, and, through boresight calibration, the datum shift and boresight angle for each model was computed. After calculating the exterior orientation of each case, the GCP (Ground Control Point) was verified using the DPW (Digital Photogrammetry Workstation). In each case, results in the boresight calibration acquired through the geoid model demonstrated a difference in the Z datum, the exterior orientation heights Z, and the rotation Ω and Φ. After utilizing the DPW in each case and comparing it to the GCP, the difference in accuracy in accordance with the geoid model was found to be within 3cm, and it was concluded that the geoid model did not have a significant impact on boresight calibration.

Achievement of Color Constancy by Eigenvector (고유벡터에 의한 색 일관성의 달성)

  • Kim, Dal-Hyoun;Bak, Jong-Cheon;Jung, Seok-Ju;Kim, Kyung-Ah;Cha, Eun-Jong;Jun, Byoung-Min
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.10 no.5
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    • pp.972-978
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    • 2009
  • In order to achieve color constancy, this paper proposes a method that can detect an invariant direction that affects formation of an intrinsic image significantly, using eigenvector in the $\chi$-chromaticity space. Firstly, image is converted into datum in the $\chi$-chromaticity space which was suggested by Finlayson et al. Secondly, it removes datum, like noises, with low probabilities that may affect an invariant direction. Thirdly, so as to detect the invariant direction that is consistent with a principal direction, the eigenvector corresponding to the largest eigenvalue is calculated from datum extracted above. Finally, an intrinsic image is acquired by recovering datum with the detected invariant direction. Test images were used as parts of the image data presented by Barnard et al., and detection performance of invariant direction was compared with that of entropy minimization method. The results of experiment showed that our method detected constant invariant direction since the proposed method had lower standard deviation than the entropy method, and was over three times faster than the compared method in the aspect of detection speed.

The study on the Base point and baseline in Korea, Japan, and China (한반도 주변의 영해기점 및 기선에 관한 연구 - 한국, 중국, 일본을 중심으로)

  • Kim, Baek-Su;Choi, Yun-Soo;Park, Byung-Moon;Jeon, Chang-Dong
    • Spatial Information Research
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    • v.16 no.3
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    • pp.331-342
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    • 2008
  • The countries are trying to expand the sea limit such as the territorial sea, fishing zone or the exclusive economic zone as far as the Law of the Sea permit to do for the benefit of their national interest. Especially, they are eager to claim the base point where it locates far from the coastline even if it is uninhabited island or reef under the sea. The baseline has been claimed to maximize the territorial sea. Another way to expand the sea limit is to lower the vertical datum to change the land limit. China claimed Dongdo which is located about 79 miles far from the coast as the base point. Japan also claimed many uninhabited island or the reef which is located very far from the coast such as Okino Dorishima. As Korea is the party who negotiate the maritime limit with Japan and China, we should be keen and sensitive on the issues claimed by neighboring countries in terms of base point and the baseline. This paper is to review the characteristics of the base points or baselines of neighboring countries and to suggest the views how to maintain and to relocate our base points. As western coast of Korean peninsula is one of the largest tide fluctuation zone in the world, with long tidal record to prove the vertical datum adjustment, Korea can find the way to lower the vertical datum especially in Yellow Sea. So, major and critical tidal station has to be set up along the western coast to verify tide fluctuation record which can be met with international standard.

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A Study on the Accuracy of GNSS Height Measurement Using Public Control Points (공공기준점을 이용한 GNSS 높이측량 정밀도 분석 연구)

  • WON, Doo-Kyeon;CHOI, Yun-Soo;YOON, Ha-Su;LEE, Won-Jong
    • Journal of the Korean Association of Geographic Information Studies
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    • v.24 no.2
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    • pp.78-90
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    • 2021
  • In order to construct a precision geoid, it has been diversified into land, sea, aviation, and satellite gravity measurement methods, and measurement technology has developed, making it possible to secure high-resolution, high-precision gravity data. The construction of precision geoids can be fast and conveniently decided through GNSS surveys without separate leveling, and since 2014, the National Geographic Information Institute has been developing a hybrid geoid model to improve the accuracy of height surveying based on GNSS. In this study, the results of the GNSS height measurement were compared and analyzed choosing existing public reference points to verify the GNSS height measurement of public surveys. Experiments are conducted with GNSS height measurements and analyzed precision for public reference points on coastal, border, and mountainous terrain presented as low-precision areas or expected-to-be low-precision in research reports. To verify the GNSS height measurement, the GNSS ellipsoid height of the surrounding integrated datum to be used as a base point for the GNSS height measurement at the public datum. Based on the checked integrated datum, the GNSS ellipsoid of the public datum was calculated, and the elevation was calculated using the KNGeoid18 model and compared with the results of the direct level measurement elevation. The analysis showed that the results of GNSS height measurement at public reference points in the coastal, border, and mountainous areas were satisfied with the accuracy of public level measurement in grades 3 and 4. Through this study, GNSS level measurement can be used more efficiently than existing direct level measurements depending on the height accuracy required by users, and KNGeoids 18 can also be used in various fields such as autonomous vehicles and unmanned aerial vehicles.

A Study on Relation Between Psychological Anxiety and Physical Performance (심리적 불안과 신체 수행도의 관계에 대한 연구)

  • 조성훈;김태성;구일섭
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.20 no.42
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    • pp.151-159
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    • 1997
  • This Study intends to analyse the degree which Psychological Anxiety affects to Physical Performance using Multivariate Statistical Analysis. For this, we accumulated two type's datum : (1)Data about Psychological anxiety by Spielberger's STAI- Ⅰ·Ⅱ, (2)Data about Physical Performance by AEFH's FITKIT.

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The 3rd order GPS Network Adjustment to Determine KGD2002 Coordinate Sets (GPS망조정에 의한 세계측지계의 3등기준점 성과산정)

  • Lee, Young-Jin;Lee, Hung-Kyu;Jeong, Kwang-Ho;Song, Jun-Ho
    • Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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    • 2007.04a
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    • pp.81-84
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    • 2007
  • This paper describes general procedure and results of the GPS 3rd odor network adjustment which has been carried out for determining coordinates sets with respect to new Korean Geodetic Datum, so-call Korean Geodetic Datum 2002 (KGD 2002). The adjustment begins with minimally constrained adjustments with respect to each of the 69 campaign networks. This was followed by constructing and adjusting sixteen block network. After detecting and removing outliers in the observation file, an attempt was made by applying the empirical stochastic modeling techniques used in the 2nd order network adjustment, so as to determine the magnitude of absolute and relative error for the estimated baseline vector from the GPS data processing. The over constrained adjustment were, in sequence, performed against each of the block network. In this adjustment, both of the 2nd order control points in the block network and the 3rd order control points overlapped with adjacent network whose coordinates were already determined from a preceding adjustment. The final adjustment results have shown that the accuracy of the 3rd order network adjustment was better than 1cm and 2cm in horizontal and vertical component, respectively.

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