• Title/Summary/Keyword: reliability space

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Strong Consistent Estimator for the Expectation of Fuzzy Stochastic Model

  • Kim, Yun-Kyong
    • International Journal of Reliability and Applications
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    • v.1 no.2
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    • pp.123-131
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    • 2000
  • This paper concerns with the consistent estimator for the fuzzy expectation of a random variable taking values in the space F($R^p$) of upper semicontinuous convex fuzzy subsets of $R^p$ with compact support. We introduce the concept of a fuzzy sample mean and show that the fuzzy sample mean is a strong consistent estimator for the fuzzy expectation. Some examples are given to illustrate the main result.

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ALMOST SURE CONVERGENCE FOR WEIGHTED SUMS OF FUZZY RANDOM SETS

  • Joo, Sang-Yeol;Kim, Yun-Kyong;Kwon, Joong-Sung
    • Proceedings of the Korean Reliability Society Conference
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    • 2004.07a
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    • pp.177-182
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    • 2004
  • In this paper, we establish some results on almost sure convergence for sums and weighted sums of uniformly integrable fuzzy random sets taking values in the space of upper-semicontinuous fuzzy sets in $R^{p}$.

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Development of De-orbiter using Drag-sail (가항력돛을 이용한 궤도이탈장치 개발)

  • Choi, Junwoo;Kim, Si-on;Lee, Joowan;Yun, Tae-gook;Kim, Byungkyu
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.45 no.1
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    • pp.63-70
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    • 2017
  • In this paper, we design and fabricate a de-orbiter using drag-sail and evaluate deployment characteristics. Without employing an actuator to deploy, the de-orbiter is activated by the SMA wire based the release mechanism and driven by the restoring force of the tape-spring. For efficient storage and deployment of drag-sail, an origami method of original ISO flasher is chosen and low priced mylar film is used as the material of the drag-sail. In addition, through the fault tree analysis method which is one of the one-shot device reliability evaluation methods, we confirm the reliability of the de-orbiter(0.997572) and the Roller failure has the highest criticality. Finally, we find feasibility of the proposed de-orbiter through the deployment demonstration of drag-sail.

Reliability of cone-beam computed tomography for temporomandibular joint analysis

  • Gorucu-Coskuner, Hande;Atik, Ezgi;El, Hakan
    • The korean journal of orthodontics
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    • v.49 no.2
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    • pp.81-88
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    • 2019
  • Objective: The aim was to assess the intraobserver and interobserver reliabilities of temporomandibular joint linear measurements and condylar shape classifications performed with cone-beam computed tomography (CBCT). Methods: CBCT images of 30 patients were measured at two different time points by two orthodontists using the Dolphin 3D program (n = 60). Anterior, posterior, and superior joint space measurements and sagittal joint morphology classification in the sagittal view and medial and lateral joint space and mediolateral width measurements and coronal joint morphology classification in the coronal view were recorded. Intraclass-interclass correlation coefficients (ICC) and kappa statistics were used to assess intraobserver and interobserver reliability for the measurements and morphology classifications, respectively. Results: The ICC values were good for measurements of the posterior joint space by observer I and for measurements of the posterior, medial, and lateral joint spaces by observer II, while the other intraobserver measurements were excellent. Only the mediolateral width measurements showed excellent interobserver ICC values, while the other measurements showed good interobserver ICC values. Intraobserver agreement for the sagittal morphology classifications was moderate (${\kappa}=0.479$) and almost perfect (${\kappa}=0.858$) for observers I and II, respectively, while the corresponding agreement for the coronal morphology classifications was substantial for both observers. The interobserver agreement values for sagittal and coronal morphology classifications were slight (${\kappa}=0.181$) and fair (${\kappa}=0.265$), respectively. Conclusions: Linear temporomandibular joint measurements were reproducible and reliable in both intraobserver and interobserver evaluations. However, interobserver agreement for assessments of condylar shape was low.

Design of ToF-Stereo Fusion Sensor System for 3D Spatial Scanning (3차원 공간 스캔을 위한 ToF-Stereo 융합 센서 시스템 설계)

  • Yun Ju Lee;Sun Kook Yoo
    • Smart Media Journal
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    • v.12 no.9
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    • pp.134-141
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    • 2023
  • In this paper, we propose a ToF-Stereo fusion sensor system for 3D space scanning that increases the recognition rate of 3D objects, guarantees object detection quality, and is robust to the environment. The ToF-Stereo sensor fusion system uses a method of fusing the sensing values of the ToF sensor and the Stereo RGB sensor, and even if one sensor does not operate, the other sensor can be used to continuously detect an object. Since the quality of the ToF sensor and the Stereo RGB sensor varies depending on the sensing distance, sensing resolution, light reflectivity, and illuminance, a module that can adjust the function of the sensor based on reliability estimation is placed. The ToF-Stereo sensor fusion system combines the sensing values of the ToF sensor and the Stereo RGB sensor, estimates the reliability, and adjusts the function of the sensor according to the reliability to fuse the two sensing values, thereby improving the quality of the 3D space scan.

Searching for Dwarf Galaxies in Deep Images of NGC 1291 obtained with KMTNet

  • Byun, Woowon;Kim, Minjin;Sheen, Yun-Kyeong;Park, Hong Soo;Ho, Luis C.;Lee, Joon Hyeop;Jeong, Hyunjin;Kim, Sang Chul;Park, Byeong-Gon;Seon, Kwang-Il;Ko, Jongwan
    • The Bulletin of The Korean Astronomical Society
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    • v.44 no.2
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    • pp.38.3-38.3
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    • 2019
  • We present newly discovered dwarf galaxy candidates in deep wide-field images of NGC 1291 obtained with KMTNet. We identify 15 dwarf galaxy candidates by visual inspection within the virial radius of NGC 1291. Using imaging simulations, we demonstrate that our imaging data is complete up to 26 mag arcsec-2 or -10 abs.mag with > 70% of the completeness rate. We also apply automated detection method to find the dwarfs. However, the completeness and the reliability are relatively low compared to the visual inspection. We find that structural and photometric properties of dwarf candidates such as effective radius, central surface brightness, Sérsic index, and absolute magnitude appear to be consistent with those of known dwarf galaxies in nearby groups and clusters, except for color. NGC 1291, residing in a relatively isolated environment, tends to accompany bluer dwarf galaxies (≃0.58) than those in denser environment. It shows that the quenching of dwarfs is susceptible to the environment.

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AKARI-FIS POINT SOURCE CATALOGUE: CURRENT STATUS AND FUTURE PLAN

  • Yamamura, Issei;Makiuti, Sin'itirou;Ikeda, Norio;Koga, Tatsuya;Yoshino, Akira;Yamauchi, Chisato
    • Publications of The Korean Astronomical Society
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    • v.27 no.4
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    • pp.105-109
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    • 2012
  • The current status of the AKARI-FIS Point Source Catalogue is reported. The first version of the Bright Source Catalogue has been in public since March 2010 and used extensively in the various fields in astronomy. The second version of the Bright Source Catalogue and the first version of the Faint Source Catalogue are currently under development. The revised Bright Source Catalogue is expected to have improved completeness, reliability, and accuracy compared to the current version. The Faint Source Catalogue will have a scan-density dependent detection limit and will enable much deeper exploration of the sky especially in the high-ecliptic latitude regions. Both catalogues will be available in a year time scale.

Behaviour Characteristic of Grid Dome Shaped Space Structures by Post-tensioning (포스트텐션에 의한 격자 돔형 공간 구조의 거동 특성)

  • 김진우
    • Journal of Ocean Engineering and Technology
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    • v.16 no.1
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    • pp.41-45
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    • 2002
  • This paper is concerned with the erection and ultimate load test of dome shaped space structures by post-tensioning. It is a fast and economical method for constructing such a dome by post-tensioning of the cable in bottom chords. This structure consists of uniform pyramids in a flat layouts on the ground, and then the structure is shaped and erected into its final curved space structure. Ultimate load test was performed for dome shaped space structures. The feasibility of the proposed erection method and the reliability of the established geometric model were confirmed with numerical analysis and experimental investigation on a small scale steel model. As a results we can find the most reasonable modeling technique for the prediction of shape formation in practices and we can know the characteristic of the behaviour in ultimate load test for practical design purposes.

Analysis of Field-Aligned Currents in the High-Altitude Nightside Auroral Region: Cluster Observation

  • Shin, Youra;Lee, Ensang;Lee, Jae-Jin
    • Journal of Astronomy and Space Sciences
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    • v.36 no.1
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    • pp.1-9
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    • 2019
  • In this paper we present analysis of current density when the Cluster spacecraft pass the nightside auroral region at about $4-5R_E$ from the center of Earth. The analysis is made when the inter-spacecraft separation is within 200 km, which allows all four spacecraft to be situated inside the same current sheet. On 22 February 2002, two field-aligned current (FAC) events were observed in both the southern and the northern hemispheres. The FACs were calculated with magnetic field data obtained by the four spacecraft using the Curlometer method. The scales of the FACs along the spacecraft trajectory and the magnitudes were hundreds of kilometers and tens of $nA/m^2$, respectively, and both events were mapped to the auroral region in the ionosphere. We also examined reliability of the results with some parameters, and found that our results are adequately comparable with other studies. Nevertheless, some limitations that decrease the accuracy of current estimation exist.

DeepSDO: Solar event detection using deep-learning-based object detection methods

  • Baek, Ji-Hye;Kim, Sujin;Choi, Seonghwan;Park, Jongyeob;Kim, Jihun;Jo, Wonkeum;Kim, Dongil
    • The Bulletin of The Korean Astronomical Society
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    • v.46 no.2
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    • pp.46.2-46.2
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    • 2021
  • We present solar event auto detection using deep-learning-based object detection algorithms and DeepSDO event dataset. DeepSDO event dataset is a new detection dataset with bounding boxed as ground-truth for three solar event (coronal holes, sunspots and prominences) features using Solar Dynamics Observatory data. To access the reliability of DeepSDO event dataset, we compared to HEK data. We train two representative object detection models, the Single Shot MultiBox Detector (SSD) and the Faster Region-based Convolutional Neural Network (R-CNN) with DeepSDO event dataset. We compared the performance of the two models for three solar events and this study demonstrates that deep learning-based object detection can successfully detect multiple types of solar events. In addition, we provide DeepSDO event dataset for further achievements event detection in solar physics.

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