• Title/Summary/Keyword: Accuracy assesment

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A Study of Three-dimensional evaluation of the accuracy of resin provisional restorations fabricated with the DLP printer (DLP 프린터로 제작된 레진 임시수복물의 3차원적 정확도 평가)

  • Kang, Wol;Lee, Hee-Kyung
    • Journal of Technologic Dentistry
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    • v.42 no.1
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    • pp.35-41
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    • 2020
  • Purpose: The purpose of this study was to evaluate the accuracy of the DLP 3D printer by conducting 3-dimensional assesment of resin provisional restorations. Methods: The first premolar of the maxillary was prepared for the abutment. The abutment was scanned by using a scanner. The provisional restoration was designed by using CAD software. A total of 16 resin provisional restorations were produced using ZD200 and Veltz DLP 3D printer. Scanning was done of resin provisional restorations and 3-dimensional measurement was conducted for accuracy. The mean (SD) of RMS was reported for each group. Independent t-test was used to assess the statistical significance of the results. All analyses were done using SPSS 22.0. Results: The mean ± SD of RMS value for the accuracy of the resin provisional restorations that was fabricated by using ZD200 and Veltz DLP 3D printer were 50.85.±4.64㎛ and 70.33±6.31㎛. Independent t-test showed significant differences between groups(p<0.001). Conclusion: The resin provisional restorations made with DLP 3D printers showed clinically acceptable accuracy.

Reliability of Load-Carrying Capacity of RC Deep Beams (철근콘크리트 깊은 보의 내하력에 대한신뢰도 평가)

  • Cheon Ju-Hyun;Kim Tae-Hoon;Lee Sang-Cheol;Shin Hyun-Mock
    • Journal of the Korea Concrete Institute
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    • v.17 no.6 s.90
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    • pp.955-962
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    • 2005
  • Still no accurate theory exists for predicting ultimate shear strength of deep reinforced concrete beams because of the structural and material non-linearity after cracking. Currently, the load capacity assesment is performed for the upper structure of the bridges and containing non-reliability in the applications and results. The purpose in this study is to evaluate analytically the complex shear behaviors and normal strength for the reinforced concrete deep beams and to offer the accuracy load capacity assesment method based on the reliability theories. This paper presents a method for the load capacity assesment of reinforcement concrete deep beams using nonlinear finite element analysis. A computer program named RCAHEST (Reinforced Concrete Analysis in Higher Evaluation System Technology), for the analysis of reinforced concrete structures was used. Material non-linearity is taken Into account by comprising tensile, compressive and shear models of cracked concrete and a model of reinforcing steel. From the results, determine the reliability index for the failure base on the Euro Code. Then, calculate additional reduction coefficient to satisfy the goals from the reliability analysis. The proposed numerical method for the load capacity assesment of reinforced concrete deep beams is verified by comparison with the others methods.

A Study on the Quality Evaluation Method of Spatial Database - Focusing on Land Database - (공간데이터베이스의 품질평가 방법에 관한 연구 - 토지데이터베이스를 중심으로 -)

  • 김미정;안종천;조우현
    • Spatial Information Research
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    • v.11 no.4
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    • pp.327-340
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    • 2003
  • Quality elements and evaluation methods should be considered according to the characteristics of spatial database. The purpose of this study is to propose specific methods for quality evaluation focusing on land database which are an important parts of spatial database. Through the study, of quality evaluation for selected quality elements are specified, which are based on the construction processes of the topogaphical database, cadastral database, and zoning database. Position accuracy, attribute accuracy, consistency, completeness, temporal accuracy, believability, and lineage are selected as the quality elements of land database. A various statistical and mathematical skills are proposed for measurement and assesment methods of quality elements.

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A Study of Analysis Method for the Track Geometry Measuring Data on High Speed Railway (고속철도 궤도검측 자료 분석기법에 관한 연구)

  • 강기동
    • Journal of the Korean Society for Railway
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    • v.7 no.4
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    • pp.291-295
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    • 2004
  • The Track geometry measuring on High-speed railway is the most important subject for the track construction and track maintenance work. Also the measuring accuracy is so significant part because it provides principle data for the maintenance plan and the assesment of working quality and can control the train speed limitation. From this point of view, it is very important to verify for the track recording coach(EM120) in KNR. According to the result of spectrum analysis, the noise near 1m waveband was found on the track recording data from EM120. So, New filter has been applied to remove the noise form track recording data. and it makes possible to acquire resembling result to real track geometry.

A Study for The Accuracy Assessment Method of Satellite Sensor Modeling (위성영상 센서모형화의 정확도 평가방법에 관한 연구)

  • Ko, Hyun-Soo;Choi, Chul-Soon;Hong, Jae-Min;Yoon, Chang-Rak
    • Journal of Korean Society for Geospatial Information Science
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    • v.13 no.2 s.32
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    • pp.79-84
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    • 2005
  • Recent researches about the accuracy assessment of the satellite sensor modeling usually focused on the quantitative analysis of errors. Quantitative error analysis contains its limitation that the distribution property of error can not be analyzed. The numerical evaluation of result of the satellite sensor modeling drop its confidence because of the absence of the distribution property of error. This study can be presented the distribution property of error to calculate RMSE and direction-coefficient of error. Moreover, Direction-coefficient which is closed to 1 s contains systematic errors. On the contrary, direction-coefficient which is closed to the zero contains random errors. To analyse the direction of errors, we will indicate that a formula is reduced the error.

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Assesment of Absorbed Dose of Organs in Human Body by Cone Beam Computed Tomography using Monte Carlo Method (몬테칼로 기법을 이용한 CBCT의 인체 내 장기의 흡수선량 평가)

  • Kim, Jong-Bo;Im, In-Chul;Park, Eun-Tae
    • Journal of radiological science and technology
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    • v.41 no.3
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    • pp.215-221
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    • 2018
  • Cone beam Computed Tomography(CBCT) is an increasing trend in clinical applications due to its ability to increase the accuracy of radiation therapy. However, this leaded to an increase in exposure dose. In this study, the simulation using Monte Carlo method is performed and the absorbed dose of CBCT is analyzed and standardized data is presented. First, after simulating the CBCT, the photon spectrum was analyzed to secure the reliability and the absorbed dose of the tissue in the human body was evaluated using the MIRD phantom. Compared with SRS-78, the photon spectrum of CBCT showed similar tendency, and the average absorbed dose of MIRD phantom was 8.12 ~ 25.88 mGy depending on the body site. This is about 1% of prescription dose, but dose management will be needed to minimize patient side effects and normal tissue damage.

Integrating Video Image into Digital Map (동영상과 수치지도의 결합에 관한 연구)

  • Kim, Yong-Il;Pyeon, Mu-Wook
    • Journal of Korean Society for Geospatial Information Science
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    • v.4 no.2 s.8
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    • pp.161-172
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    • 1996
  • The objective of this research is to develope a process of integrating video image into digital map. In order to reach the research objective, the work includes the development of georeferencing technique for video images, the development of pilot system and the assesment process. Georeferencing technique for video images is composed of DGPS positioning, filtering of abnormal points, map conflation, indexing locations for key frames via time tag and indexing locations for total frames. By using the proposed building process, we could find the result that the accuracy of image capturing test points is $92.8%({\pm}2\;frames)$. The eventual meaning of this study is that it is possible to find a new conception of digital map, which overcomes a limitation of exiting two dimensional digital map.

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Measurement and Analysis of Rodent Biological Signals using Telemetry System (원격측정장치를 이용한 설치류의 생체신호 측정 및 분석)

  • Kim, Chang-Hwan;Hur, Gyeong-Haeng
    • Journal of the Korea Institute of Military Science and Technology
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    • v.14 no.6
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    • pp.1159-1165
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    • 2011
  • Telemetry techniques of rats have been used for assessing safety pharmacology of drugs and chemicals. Biological signals including blood pressure and heart rate measured under anesthesia were significantly different from those obtained under normal conditions. The stress of restraint in awake animals can also affect the accuracy of physiological evaluation. This paper details the surgery required to allow key cardiovascular parameters to be determined. The telemetric measurement of cardiovascular parameters such as blood pressure, heart rate, electrocardiograph(ECG) established. We carried out the continuous monitoring of cardiovascular parameters using the telemetry system in F344 rats. During the measurement, no significant changes were observed in the heart rate and blood pressure. ECG signals and body temperature were also constant during the measurement of biological signals. With the results of this study, we conclude that this telemetry system can be applied usefully for the assesment of biological parameters in the rats.

Assesment of accuracy of the radar rainfall estimation for KICT X-band dualpolarization radar (KICT X밴드 이중편파레이더의 레이더 강우량 정확도 평가)

  • Yoon, Jungsoo;Hwang, Seokhwan;Oh, Byunghwa;Kang, Narae
    • Proceedings of the Korea Water Resources Association Conference
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    • 2017.05a
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    • pp.246-246
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    • 2017
  • 서울과 같은 대도시 지역은 인구와 산업이 집중되어 있기 때문에 작은 규모의 수재해로도 큰 피해를 입을 수 있다. 또한 국지적으로 발생하는 집중호우는 도시 지역에 돌발홍수를 일으킬 수 있기 때문에 국지 예보는 도시 지역에서 매우 중요한 역할을 하고 있다. 레이더는 먼 거리에서의 악기상을 빠르게 관측할 수 있기 때문에 도시 지역 수재해 방지에 큰 역할을 할 것으로 기대되고 있다. 특히 X 밴드레이더는 높은 시공간 해상도의 관측 자료를 제공하고 있어 도시 지역에 적합한 레이더로 알려져 있다. 국내에는 건술기술연구원, 고려대학교, 연세대학교에 X밴드 이중편파레이더가 도입되어 서울 지역에서의 수재해 감시 역할을 수행하고 있다. X밴드 이중편파레이더는 반사도, 차등반사도, 차등위상차, 비차등위상차 등 다양한 레이더 편파변수들을 제공하고 있다. 이중 비차등위상차는 감쇄와 부분차폐의 영향을 받지 않아 비차등위상차로부터 추정된 레이더 강우는 큰 강우 강도에서 정확도가 높은 것으로 알려져 있다. 본 연구에서는 이러한 비차등위상차로부터 추정된 레이더 강우량에 대한 정확도를 평가하였다. 이를 위해 2013년부터 2016년까지 관측된 건설기술연구원 X밴드 이중편파레이더 자료(42개 강우사례)를 활용하였다.

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