• Title/Summary/Keyword: Observers

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AN EXPERIMENTAL STUDY ON THE EFFECT OF INTERNAL DISCOLORATION OF TEETH BY ENDODONTIC SEALERS (수종(數種) 근관(根管) 충전재(充塡材)에 의(依)한 치아(齒牙) 내부(內部) 변색효과(變色效果)에 관(關)한 실험적(實驗的) 연구(硏究))

  • Geol, Kim-In;Cho, Jae-O
    • Restorative Dentistry and Endodontics
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    • v.12 no.2
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    • pp.65-72
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    • 1987
  • The purpose of this study was to examine the influence of several root canal sealers on the discoloration of internal surface after root canal obstruction. Twenty four sound human premolars, extracted for orthodontic or prosthodontic purposes, were randomly selected and divided into eight groups. Extracted premolars were prepared, and the following seven materials were introduced into the pulp cavities: AH 26, Fuji ionomer (Type I) cement, N2, Oxypara "Murakami", Kerr sealer, PCA sealer, and G-C's Propac ZOE cement. After 7 weeks of incubation; the discolored tooth crowns were hemisectioned, and the internal staining patterns were examined. Then, with an association of observed values the mean intensity scores and percentage of coverage scores of the internal staining patterns in teeth attained by two observers using for Chisquare test were analyzed. The results were as follows: 1. All the experimental premolar's crown showed various ranged discoloration of internal surface. 2. There was no significance between the association scores of two observers participated into this experiments:% coverage scores (P > 0.05) and intensity (P > 0.05) 3. The crowns filled with PCA sealer, AH 26, and Fuji ionomer cement was visible within a depth of one third of dentin. (P> 0.05) 4. For N2, Kerr sealer, and G-C's Propac cement, A slight dentinal staining was recorded, which penetrated up to half way into the dentin. (P> 0.05) 5. It was noticed that the teeth filled with Oxypara "Murakami" were discolored more than two thirds of the dentinal layer. 6. On the control group, there was no discoloration.

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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.

An Analysis of the Visual Attention on the Urban Landscape with Pilotis Space using Eye Tracking in terms of the Conception of 'Space and Infinity' ('공간과 무한성' 개념의 측면에서 도시경관에 대한 시각적 분석 - 필로티 공간의 유무에 따른 아이트래킹 기법 실험분석을 바탕으로 -)

  • Cho, Hyeong-Kyu
    • Journal of the Architectural Institute of Korea Planning & Design
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    • v.34 no.6
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    • pp.23-30
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    • 2018
  • Gordon Cullen, who tried to understand urban landscapes in terms of visual attention, introduced a concept called 'Space and Infinity' in his book 'Townscape'. According to him, urban images like infinity spreading across the sky are more effectively created when we happen to see an open space while walking along a ground-level street than when we look at the sky. This study aims to quantitatively examine if urban observers pay more attention to spaces like pilotis on the bottom of a building. Thus, this study collected observers on actual urban landscape images and partially-edited images and conducted an experiment by adopting Eye-movement Tracking to find out if they actually pay more visual attention to a space like pilotis. This study selected a total of 50 people as research subjects and divided them into two groups. Image 1 was shown to one group, and Image 2 with the pilotis space edited was shown to the other group. As an experiment to find objective evidences on Gordon Cullen's 'Space and Infinity', this study analyzed difference between Image 1 and Image 2, and it was found that the domain of pilotis showed a value five times higher than the average visual attention since it attracted much visual attention although it was very small in area. That is, it has objectively clarified that people get most fascinated with a place with infinite images in the background like a pilotis space out of all the urban landscapes as Gordon Cullen's theory. In addition, the differences in visual concentration of pilotis space by sex, by subject was examined, and there was no significant difference in visual concentration of pilotis space by gender. As a result of examining the difference of visual concentration by classifying the subjects into architectural related major, the major group showed higher frequency of viewing than the non - major group.

Real Time Versus Photographic Assessment of Stool Consistency Using the Brussels Infant and Toddler Stool Scale: Are They Telling Us the Same?

  • Aman, Berthold Albert;Levy, Elvira Ingrid;Hofman, Benjamine;Vandenplas, Yvan;Huysentruyt, Koen
    • Pediatric Gastroenterology, Hepatology & Nutrition
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    • v.24 no.1
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    • pp.38-44
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    • 2021
  • Purpose: Digital communication is becoming increasingly important in clinical practice and research. The finding that stool consistency can be evaluated similarly using either "in vivo" or photographic material by health care professionals will decrease subjective interpretation by parents. The primary outcome of this study was the reliability of stool consistency scoring using the Brussels Infant and Toddler Stool Scale (BITSS) between fresh stools and their photos; the secondary outcome was the inter-rater reliability based on the fresh stools. Methods: Fresh stool samples from healthy children were collected in a day care center. These stools, and one month later the corresponding photos presented in a random order, were presented to 14 observers. Reliabilities were analyzed using absolute agreements and weighted and unweighted Cohen's κ. Results: In total, 202 samples were rated 576 times. Absolute agreement between photographic and real time assessment ranged between 71.1% and 83.3% among observers. This corresponded with substantial agreement (unweighted κ=0.70 [95% CI, 0.61-0.78]; weighted κ=0.86 [95% CI, 0.78-0.88]). The inter-observer agreement showed similar percentages of absolute agreement (81.4-82.0%) and κ-values corresponding with fair-to-moderate agreement. Conclusion: Our findings suggest that the assessment of fresh stool consistency can also reliably be done on photographic material when using the BITSS. This opens opportunities in scientific surroundings and in our daily life communication with parents and caretakers.

Methodology for the Observations of Stellar Occultations by Small Bodies of the Solar System

  • Salazar-Manzano, Luis E.;Quintero, Edwin A.
    • Journal of Astronomy and Space Sciences
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    • v.38 no.1
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    • pp.1-21
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    • 2021
  • The observation of stellar occultations constitutes one of the most important techniques for determining the dimensions and establishing the physical parameters of small Solar System bodies. The most substantial calculations are obtained from multiple observations of the same event, which turns the observation of stellar occultations into highly collaborative work and groups teams of observers through international networks. The above situation also requires the participation of both professional and amateur observers in these collaborative networks. With the aim of promoting the participation of professional and amateur groups in the collaborative observation of stellar occultations, we present the methodology developed by the Astronomical Observatory of the Technological University of Pereira (OAUTP) for the observations of occultations due small Solar System bodies. We expose the three fundamental phases of the process: the plan to make observations, the capture of the events, and the treatment of the data. We apply our methodology using a fixed station and a mobile station to observe stellar occultations due to MBAs (354) Eleonora (61) Danae (15112) Arlenewolfe (3915) Fukushima (61788) 2000 QP181 (425) Cornelia (257) Silesia (386) Siegena and (41) Daphne, and due to TNOs 1998BU48 and (529823) 2010 PP81. The positive detections for the objects (257) Silesia (386) Siegena and (41) Daphne allow us to derive lower limits in the diameter of the MBAs of 63.1 km, 166.2 km and 158.7 km and offsets in the astrometric position (Δαc cos��c, Δ��c) of 622.30 ± 0.83, 15.23 ± 9.88 mas, 586.06 ± 1.68, 43.03 ± 13.88 mas and -413.44 ± 9.42, 234.05 ± 19.12 mas, respectively.

Preliminary study on spatio-temporal variations of five giant and 17 large fish species around the Korean peninsula from 2011 to 2016

  • Kim, Jin-Koo;Kim, Hyung Chul;Ryu, Jung-Hwa;Ahn, Ji-Suk
    • Fisheries and Aquatic Sciences
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    • v.25 no.5
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    • pp.298-310
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    • 2022
  • Although giant and large fish species are highly important as a keystone species in the marine ecosystem, there have been no or few studies on their spatio-temporal variations around the Korean peninsula. For this, we analyzed daily reports made by observers at 57 fishery landing sites in Korea over 6 years, from 2011 to 2016. In total, 153 fish species were re-identified based on photos and descriptions recorded by Korean observers, of which five species were classified as a giant fish over 5 m in maximum total length (MTL) and 17 species as a large fish from 3 m to 5 m MTL according to the data presented by Froese & Pauly (2021). Among the giant and large fish species, Mola mola was the most abundant species, with 75 individuals landed as by-catch. The second most abundant species was Isurus oxyrinchus (31), followed by Mobula mobular (23), Lamna ditropis (17), Masturus lanceolatus (16), Sphyrna zygaena (14), and Prionace glauca (12). As a result of cluster analysis based on the number of individuals of giant and large fish species by year and sea, six years were separated into two clusters (2011-2013 vs. 2014-2016), with high contribution of M. mola, I. oxyrinchus, and M. lanceolatus; and three seas were separated into two clusters (eastern + southern seas vs. western sea), with high contribution of M. lanceolatus, L. ditropis, and I. oxyrinchus. The largest number of M. mola accounted for 64% of the total in 2014 and 2016, and 71% in summer (June-August). It is assumed to have a correlation between seawater temperature fluctuation and the occurrence of giant and large fish species. Our study highlights importance of longterm monitoring of giant and large fish species, and can help to understand the life cycle such as natal or nursery migration of giant and large fish species around the Korean peninsula.

The Vectra M3 3-dimensional digital stereophotogrammetry system: A reliable technique for detecting chin asymmetry

  • Hansson, Stina;Ostlund, Emil;Bazargani, Farhan
    • Imaging Science in Dentistry
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    • v.52 no.1
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    • pp.43-51
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    • 2022
  • Purpose: The aim of this study was to evaluate the reliability of the Vectra M3 (3D Imaging System; Canfield Scientific, Parsippany, NJ, USA) in detecting chin asymmetry, and to assess whether the automatic markerless tracking function is reliable compared to manually plotting landmarks. Materials and Methods: Twenty subjects (18 females and 2 males) with a mean age of 42.5±10.5 years were included. Three-dimensional image acquisition was carried out on all subjects with simulated chin deviation in 4 stages (1-4 mm). The images were analyzed by 2 independent observers through manually plotting landmarks and by Vectra software auto-tracking mode. Repeated-measures analysis of variance and the Tukey post-hoc test were performed to evaluate the differences in mean measurements between the 2 operators and the software for measuring chin deviation in 4 stages. The intraclass correlation coefficient (ICC) was calculated to estimate the intra- and inter-examiner reliability. Results: No significant difference was found between the accuracy of manually plotting landmarks between observers 1 and 2 and the auto-tracking mode (P=0.783 and P=0.999, respectively). The mean difference in detecting the degree of deviation according to the stage was <0.5 mm for all landmarks. Conclusion: The auto-tracking mode could be considered as reliable as manually plotted landmarks in detecting small chin deviations with the Vectra® M3. The effect on the soft tissue when constructing a known dental movement yielded a small overestimation of the soft tissue movement compared to the dental movement (mean value<0.5 mm), which can be considered clinically non-significant.

Intraoral scanning of the edentulous jaw without additional markers: An in vivo validation study on scanning precision and registration of an intraoral scan with a cone-beam computed tomography scan

  • Julie Tilly Deferm;Frank Baan;Johan Nijsink;Luc Verhamme;Thomas Maal;Gert Meijer
    • Imaging Science in Dentistry
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    • v.53 no.1
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    • pp.21-26
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    • 2023
  • Purpose: A fully digital approach to oral prosthodontic rehabilitation requires the possibility of combining (i.e., registering) digital documentation from different sources. This becomes more complex in an edentulous jaw, as fixed dental markers to perform reliable registration are lacking. This validation study aimed to evaluate the reproducibility of 1) intraoral scanning and 2) soft tissue-based registration of an intraoral scan with a cone-beam computed tomography (CBCT) scan for a fully edentulous upper jaw. Materials and Methods: Two observers independently performed intraoral scans of the upper jaw in 14 fully edentulous patients. The palatal vault of both surface models was aligned, and the inter-observer variability was assessed by calculating the mean inter-surface distance at the level of the alveolar crest. Additionally, a CBCT scan of all patients was obtained and a soft tissue surface model was generated using patient-specific gray values. This CBCT soft tissue model was registered with the intraoral scans of both observers, and the intraclass correlation coefficient(ICC) was calculated to evaluate the reproducibility of the registration method. Results: The mean inter-observer deviation when performing an intraoral scan of the fully edentulous upper jaw was 0.10±0.09 mm. The inter-observer agreement for the soft tissue-based registration method was excellent(ICC=0.94; 95% confidence interval, 0.81-0.98). Conclusion: Even when teeth are lacking, intraoral scanning of the jaw and soft tissue-based registration of an intraoral scan with a CBCT scan can be performed with a high degree of precision.

Identification of Problems and Improvement Measures of Fire Observer Operation in Domestic Manufacturing Industry (국내 제조업 화재감시자 운영의 문제 확인 및 개선방안)

  • Kyung Min Kim;Yongyoon Suh;Jong Bin Lee;Seong Rok Chang
    • Journal of the Korean Society of Safety
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    • v.38 no.6
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    • pp.26-35
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    • 2023
  • Sparks cause most fire and explosion accidents in the manufacturing industry during hot work, which ignites surrounding combustible materials. Such incidents lead to high casualties due to suffocation from toxic gases and lack of evacuation. Therefore, the government recently enacted and revised 'The Occupational Safety and Health Act' to prevent fires and explosions at work sites, incorporating legal standards for fire observers, which are important in preventing accidents and the spread of fire during hot work. However, there are notable shortcomings in conducting professional cause analysis of these accidents and in aligning them with advanced foreign legal standards. Additionally, there is a lack of literature review reflecting the manufacturing industry characteristics. Despite the recent enactment and revision of legal standards, gathering sufficient opinions and professional reviews remains insufficient. To address these gaps, interviews were conducted with safety and health workers, analyzing recent fire and explosion causes in domestic manufacturing industries, and reviewing both domestic and international legal standards. Conclusively, proposed improvement measures were centered on the professionalization of fire observer education, enhancing their roles and authority realistically, and improving fire observer placement and operation standards. Consequently, additional 'Occupational Safety and Health Act' standards are necessary for fire observer education and defining the government's role. Second, precise legal standards outlining the role and authority of fire observers are required. Third tailored fire observer arrangements and management standards appropriate for varying work characteristics and company sizes are required. This study emphasizes the importance of supplementing relevant legal standards to prevent fire accidents in the manufacturing industry.

Usefulness of MRI 3D Image Reconstruction Techniques for the Diagnosis and Treatment of Femoral Acetabular Impingement Syndrome(Cam type) (대퇴 골두 충돌 증후군(Cam type)의 진단과 치료를 위한 자기공명 3D 영상 재구성 기법의 유용성)

  • Kwak, Yeong-Gon;Kim, Chong-Yeal;Cho, Yeong-Gi
    • The Journal of the Korea Contents Association
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    • v.15 no.11
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    • pp.313-321
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    • 2015
  • To minimize CT examination for Hip FAI diagnosis and operation plan. also, whether the MRI 3D images can replace Hip Clock face image was evaluated when performing Hip FAI MRI by using additional 3D image. This study analyzed Hip MRI and 3D Hip CT images of 31 patients in this hospital. For the purpose of evaluating the images, one orthopedic surgeon and one radiology specialist reconstructed Clock face, at MR and CT modality, by superior 12 o'clock, labrum front 3 o'clock, and the other side 9 o'clock, centering on Hip joint articular transverse ligament 6 o'clock. Afterwards, by the Likert Scale 5 point scale (independent t-test p<0.005), this study evaluated the check-up of A. retinacular vessel, B. head neck junction at 11 o'clock, A. Epiphyseal line, B. Cam lesion at 12 o'clock, and Cam lesion, Posterior Cam lesion at 1,2,3 and 4 o'clock. As for the verification of reliability among observers, this study verified coincidence by Cohen's weighted Kappa verification. As a result of Likert scale for the purpose of qualitative evaluation about the image, 11 o'clock A. retinacular vessel MR average was $3.69{\pm}1.0$ and CT average was $2.8{\pm}0.78$. B. head neck juncton didn't have a difference between two observers (p <0.416). 12 o'clock A. Epiphyseal line MR average was $3.54{\pm}1.00$ and CT average was $4.5{\pm}0.62$(p<0.000). B. Cam lesion didn't have a difference between two observers (p <0.532). 1,2,3,4 Cam lesion and Posterior Cam lesion were not statistically significant (p <0.656, p <0.658). As a result of weighted Kappa verification, 11 o'clock A.retinacular vessel CT K value was 0.663 and the lowest conformity. As a result of coincidence evaluation on respective item, a very high result was drawn, and two observers showed high reliability.